When Is Knee Pain Serious? Warning Signs

Summary: Sudden swelling, deformity, inability to put weight on the knee, locking, fever or knee pain beginning after trauma should be evaluated without delay. If severity increases rapidly or the knee cannot be moved, A&E may be needed. The location of pain is as important as how it started and what other symptoms are present.

Knee pain is considered serious when it indicates a condition requiring prompt evaluation, such as fracture, infection, ligament or meniscus injury in the joint. Particularly pain arising from falls, impact or sudden twisting movements, if accompanied by obvious swelling, feeling of instability, restricted movement or inability to bear weight, should not be delayed.

Not all knee pain means the same thing. Pain in the kneecap when climbing stairs differs from changes in the shape of the knee after trauma and requires different priorities. For example, being 55 years of age or older is one of the criteria in the Ottawa Knee Rules used when evaluating the need for direct radiography due to fracture risk (PMID 37874571). For this reason, the right question is not just "How does knee pain go away?" but rather "How quickly does each symptom need evaluation?"

What is Knee Pain and When Should It Be Taken Seriously?

Knee pain is pain and restricted movement arising from the knee joint and surrounding tissues including bone, cartilage, ligaments, tendons or muscles. Pain that begins after sudden trauma, prevents weight-bearing, has rapidly increasing swelling, or is accompanied by fever and redness should be taken seriously; gradually worsening symptoms should also be evaluated without delay.

The knee is composed of 3 main compartments: the inner and outer tibiofemoral regions and the patellofemoral region where the kneecap contacts the thigh bone. This structure is accompanied by menisci, anterior and posterior cruciate ligaments, collateral ligaments, muscles and tendons. For this reason "knee pain" does not describe a single disease but the common symptom of various problems affecting different tissues. (PMID 21540705 — Normal anatomy and biomechanics of the knee, 2011)

When assessing the seriousness of pain, the following features should be considered:

• How it started: Pain that begins suddenly after a fall, impact or twisting movement may be associated with ligament, meniscus or bone injury.
• Loss of function: Inability to bear weight on the knee, difficulty walking, inability to straighten or bend the knee or sensation of locking requires evaluation.
• Accompanying signs: Obvious swelling, change in shape, redness, increased warmth or fever are signs that warrant more careful attention.
• Course: Symptoms that do not improve with rest, are getting worse or significantly restrict daily movement should not be delayed.
• Personal medical history: Recent surgery, presence of a knee prosthesis, a condition that increases infection risk, or a history of treatment affecting immunity may alter the timing of assessment.

Kneecap pain that appears when climbing stairs, squatting or after prolonged sitting is often associated with the patellofemoral region. Muscle and tendon complaints developing after overuse are also common. By contrast, if there is sudden loss of function, rapidly increasing swelling or signs of general illness, you should not expect the pain to resolve on its own.

In assessment, how pain began, how much the knee can be used, and what other symptoms accompany the condition matter as much as pain severity. In acute and long-standing knee pain, history and physical examination help determine whether imaging is needed and which direction the correct approach should take. (PMID 37874571 — Evaluation and Treatment of Knee Pain: A Review, 2023)

Which Knee Pain Symptoms Require Emergency Evaluation?

Obvious deformity of the knee, open wound or uncontrolled bleeding; cold, pale or numb foot; inability to bear weight after trauma; and rapidly increasing swelling all require emergency evaluation. Fever or general deterioration accompanying a red and warm knee also should not be delayed due to risk of joint infection.

Symptoms requiring 112 or emergency department evaluation

The following findings may indicate an injury affecting not just the knee joint but also circulation, nerves or the person's general condition:

• Loss of the knee's natural shape after a fall, traffic accident or sports injury
• Open wound with visible bone, uncontrolled bleeding or foreign object embedded
• The foot on the injured side suddenly appears cold, pale or purple
• Marked numbness in the foot, loss of feeling or inability to move the toes
• Fainting, confusion or marked general deterioration alongside knee pain
• Sudden breathlessness, chest pain, fainting sensation or rapidly developing swelling in one leg in a person who has recently had surgery

With these symptoms, the person should not be forced to walk, and no attempt should be made to straighten a dislocation or fracture by hand. If safe transport is not possible, 112 should be called.

Conditions requiring assessment on the same day

Some symptoms, although they may not require an ambulance, should not be left until the next day:

• Marked swelling of the knee in a short time
• Unable to take even a few steps or weight-bear on the knee after the trauma
• Locking of the knee; inability to straighten the leg fully or to bend it
• Marked redness around the knee, increased warmth and tenderness
• Fever of 38°C or above accompanied by chills, fatigue or warm, swollen knee
• Rapid increase in pain, including pain at the kneecap, following a fall or impact
• Newly developed calf swelling, tightness or one-sided colour change
• New onset swelling, increased warmth, wound discharge or fever in a person with a knee prosthesis

Fever below 38°C does not exclude joint infection. Infection may present with milder symptoms, particularly in immunocompromised individuals, older adults and those who have recently undergone knee surgery.

What might each symptom suggest?

Symptom pattern	Why it should not be delayed?	When to seek care
Deformity, open wound, cold or numb foot	Possible fracture, dislocation, blood vessel or nerve injury	112 or emergency department
Red, warm knee, fever, shivering	Possible joint infection	Same day; emergency department if general condition is poor
Rapid swelling after trauma and inability to weight-bear	Possible fracture, ligament injury or bleeding inside the joint	Same day
Knee locking	Possible injury mechanically blocking joint movement	Same day
Post-surgical breathlessness or chest pain	Possible emergency such as blood clot in lung artery	112
New discharge, warmth and swelling around prosthetic knee	Possible periprosthetic infection	Same day

In acute knee pain, the decision is not based solely on pain severity; the type of trauma, how rapidly swelling develops, joint mobility, foot circulation and accompanying systemic symptoms are evaluated together. During examination, time-sensitive causes such as fracture, ligament damage, infection and blood vessel or nerve injury are investigated first.

Source: PMID 37414429 — Acute knee pain (2023).

What Are the Serious Causes of Knee Pain?

Serious causes of knee pain include joint infection, fracture or dislocation, major ligament and meniscus injuries, advanced osteoarthritis, inflammatory rheumatoid disorders, and rarely bone or soft tissue tumours. Severity is evaluated not only by pain intensity but also by trauma type, fever, swelling, loss of movement and changes in general condition.

Structural Damage Following Trauma

Pain beginning after a fall, collision or sudden twisting of the knee may be associated with fracture, dislocation or ligament injury. Particularly if there is inability to weight-bear, rapidly developing swelling, or marked changes in the shape of the knee, this suggests damage beyond simple muscle strain.

The knee contains 4 main ligaments contributing to joint stability and 2 menisci helping distribute load. Tearing of the ligaments, particularly the anterior cruciate ligament, or a displaced tear in the meniscus can cause the knee to give way or lock. For knee anatomy and biomechanics: Normal anatomy and biomechanics of the knee (PMID 21540705).

Serious traumatic causes include:

• Fracture of bones around the knee
• Dislocation of the kneecap or knee joint
• Anterior or posterior cruciate ligament injury
• Lateral or medial collateral ligament damage
• Meniscus tear blocking knee movement
• Multiple ligament injury occurring simultaneously

Infection and Inflammatory Joint Diseases

Joint infection is one of the causes of knee pain requiring prompt evaluation. Pain may be accompanied by increased warmth, redness, marked swelling, fever or general deterioration. Symptoms may not look the same in every person, so the absence of fever alone does not rule out infection.

In a person with a knee prosthesis, new onset swelling, pain at rest, changes around the wound or discharge are evaluated for periprosthetic infection. This presentation may occur in the early postoperative period or develop long after surgery. Diagnosis is based not solely on imaging but on examination, blood tests and, if necessary, analysis of joint fluid. For periprosthetic infection criteria: The 2018 Definition of Periprosthetic Hip and Knee Infection: An Evidence-Based and Validated Criteria (PMID 29551303).

In rheumatoid arthritis and other inflammatory rheumatoid diseases, knee pain may be accompanied by prolonged morning stiffness, swelling in multiple joints or periodic flare-ups. These symptoms require a different evaluation than mechanical causes of kneecap pain.

Advanced Osteoarthritis and Joint Surface Damage

Knee osteoarthritis is a process affecting cartilage along with bone, ligaments and surrounding muscles. Pain that markedly interferes with daily walking, stair use or night sleep, or the development of shape changes or loss of movement in the knee, may indicate increasing impact of the disease on function.

The severity of osteoarthritis is not determined solely by X-ray findings of wear. Examination findings, the person's movement capacity, the course of pain and functional limitations in daily life are considered together. For general approach to knee pain evaluation and treatment options: Evaluation and Treatment of Knee Pain: A Review (PMID 37874571).

Less Common But Important Causes Not to Be Missed

Not all knee pain originates directly from the knee joint. Hip disease or nerve root involvement can cause pain to be referred to the knee. Particularly if knee examination does not explain the pain, the hip and lumbar region are included in the evaluation.

Less common but important causes include:

• Tumours developing in bone or soft tissue
• Circulation disorders
• Pain radiating to the knee due to nerve root compression
• Pain referred from the hip joint
• Bleeding inside the joint
• Systemic diseases affecting the immune system

Pain accompanied by night-time intensification, progressive or unexplained weight loss, and general deterioration warrants investigation of its cause. A single symptom does not establish a diagnosis; correct differentiation is made through examination and necessary investigations. Should a surgical approach be considered, planning is individualised and outcomes of any surgical or interventional procedure may vary from person to person.

What Pain Location Tells You: Kneecap, Front, Back and Lateral Regions

Pain location does not alone determine the affected structure; however, it narrows down possible causes. Pain over the kneecap and front of the knee is often associated with patellofemoral structures; back pain with tendons or tissues behind the knee; and lateral pain with ligaments and surrounding soft tissues. Swelling, locking and history of trauma guide the assessment.

What does kneecap and front-of-knee pain suggest?

Kneecap pain, particularly when it worsens going down stairs, squatting, or standing up after prolonged sitting, may be associated with patellofemoral pain. This presentation is evaluated alongside load distribution around the kneecap and muscle control; diagnosis is not made solely on the basis of where the pain is felt.

Pain in the front region may have different meanings in the following situations:

• Kneecap pain worsening with stairs and squatting: May require assessment of the patellofemoral joint and muscle balance around it.
• Pain felt just below the kneecap: May be associated with overloading of the patellar tendon; particularly common after activities involving running and jumping.
• Pain over the kneecap starting after a fall: Investigated for possible injury to bone, cartilage or surrounding soft tissues.
• Front-of-knee pain accompanied by swelling and restricted movement: May require more comprehensive assessment than simple load-related discomfort.

In patellofemoral pain, the timing of symptom onset, which movements aggravate it, and how the pain changes after rest are as important as the location of the complaint. Assessment also takes into account control of the hip and thigh muscles.
Source: PMID 30633480 — Patellofemoral Pain Syndrome (2019); PMID 31475628 — Patellofemoral Pain (2019).

What can pain behind the knee mean?

Pain behind the knee may arise from various causes ranging from muscle and tendon strain to fluid accumulation behind the knee. Pain may be referred from the hip or from compression of a nerve root in the lower back to the knee region, so focusing only on the back of the knee is not always appropriate.

The following features help guide assessment:

• Sensation of tightness or fullness when bending the knee
• Tenderness in the back region appearing after exercise
• Swelling noticed behind the knee
• Pain radiating to the calf or sudden calf swelling
• Knee pain appearing at the same time as hip or back symptoms

If pain behind the knee is accompanied by sudden calf swelling, warmth, colour change or breathlessness, do not wait; obtain urgent medical evaluation.

How is pain on the inner and outer sides of the knee interpreted?

Lateral region pain is evaluated based on whether the pain is on the inner or outer side and how it began. On the inner side of the knee, the joint line, surrounding ligaments and tendons are considered; on the outer side, the lateral collateral ligament and structures such as the iliotibial band are noted.

Location of pain	Associated clue	Structures that may be assessed
Medial (inner) side	Twisting, change of direction, or tenderness at the joint line	Medial ligament, medial joint compartment and surrounding tendons
Lateral (outer) side	Burning sensation worsening with running or feeling of repetitive friction	Iliotibial band and lateral soft tissues
Lateral side, after trauma	Lateral stress to the knee and sensation of instability	Lateral collateral ligament and adjacent structures
Widespread lateral pain	Swelling, restricted movement or difficulty bearing weight	Various structures within and around the joint

The knee is supported by 4 main ligaments which assist in maintaining balance during movement. However, not all pain felt in the lateral region indicates ligament injury; the location of tenderness on examination, knee stability, and the mechanism of injury are considered together.
Source: PMID 21540705 — Normal anatomy and biomechanics of the knee (2011); PMID 29443704 — Lateral Collateral Ligament Injury About the Knee: Anatomy, Evaluation, and Management (2018); PMID 32514741 — Ultrasound of iliotibial band syndrome (2020).

Changes in pain location, whether it spreads from a single point throughout the knee, or whether it changes with hip and ankle movements should also be noted. The map of pain is an important clue; what determines the diagnosis is the interpretation of this map together with history of trauma, symptoms, examination findings and, where necessary, imaging results.

How Are Ligament, Meniscus and Muscle Injuries Distinguished?

Ligament, meniscus and muscle injuries are distinguished by evaluating together how they occurred, pain location, timing of swelling, sensation of locking or giving way, and examination findings. Instability is typical of ligament injury; pain at the joint line with catching in meniscal injury; and localised tenderness worsening with movement or muscle contraction in muscle-tendon injury.

Why is what happened at the moment of injury important?

The force the knee sustained provides the first clue about which tissue may have been affected:

• Ligament injury: Can occur following twisting of the knee with the foot fixed in place, sudden change of direction, or forced lateral deviation of the knee. A 'tearing' or 'popping' sensation may be reported at the time of injury. The person may experience apprehension that the knee will give way during walking.
• Meniscus injury: Pain that occurs during squatting, twisting, or straightening under load is typical. Tenderness along the inner or outer joint line of the knee, a catching sensation, and reduced range of movement may be experienced.
• Muscle or tendon injury: Pain at a specific point develops after running, jumping, sudden acceleration, or overstretching. The pain typically becomes more pronounced when the affected muscle is contracted or stretched.

How are symptoms compared?

Findings	Ligament injury	Meniscus injury	Muscle-tendon injury
Common mechanism of onset	Twisting, sideways force, sudden change of direction	Twisting or squatting under load	Sudden muscle contraction, acceleration, jumping, overstretching
Location of pain	Along the ligament affected; front, inner or outer side of the knee	At the inner or outer joint line	More localised area over the muscle or tendon
Associated feeling	Giving way, instability	Catching, locking, friction sensation	Pulling, burning or pain with muscle contraction
Swelling	May develop within the first few hours in some serious injuries	May be noticed within hours or the next day	Superficial swelling or bruising may be visible
Relationship to movement	May worsen with change of direction and lateral loading	May worsen with squatting, twisting and full knee bending	May worsen with active use of the affected muscle

Ligament injuries are classified clinically as Grade 1, 2 and 3. This classification describes the degree of damage to fibres and the laxity present in the knee. In the evaluation of lateral ligament injury in particular, the mechanism of injury, regional tenderness and examination tests that assess medial-lateral stability are considered together. Source: PMID 29443704 — Lateral Collateral Ligament Injury About the Knee: Anatomy, Evaluation, and Management (2018).

Are locking and restriction of movement due to pain the same thing?

In true locking, the knee remains fixed at a certain angle due to a mechanical obstruction and cannot fully extend. In pain-related movement restriction, a person is unable to complete the movement because they are guarding against pain. This distinction is important when evaluating the meniscus; however, orthopaedic examination is needed to confirm it.

The following findings warrant urgent evaluation:

• Unable to bear weight on the knee after injury
• Marked swelling within the first few hours
• Recurrent giving way of the knee
• Locking that prevents full extension
• Change in shape around the kneecap
• Marked muscle weakness or inability to actively straighten the knee

On examination, ligament integrity, meniscal tests, muscle strength and range of motion are assessed. Where necessary, X-rays can be used to evaluate bone injuries, and magnetic resonance imaging to detail ligaments, menisci and other soft tissues. The need for imaging is determined by the mechanism of injury and physical examination findings. Source: PMID 37874571 — Evaluation and Treatment of Knee Pain: A Review (2023).

How Does the Diagnostic Process for Knee Pain Progress?

The diagnostic process for knee pain begins with history and physical examination; imaging is not ordered in the same sequence for every patient. The doctor assesses the onset of pain, any trauma, swelling, locking and weight-bearing status. Based on findings, X-ray, ultrasound or MRI is selected; where infection or inflammation is suspected, blood tests and joint fluid analysis may be considered.

What is assessed in the history and examination?

The character of pain matters, not just its location. Pain arising from a sudden twisting movement is not evaluated in the same way as kneecap pain that has worsened over months. During examination, the following points are typically assessed:

• Whether pain is felt on the front, back, inner or outer side of the knee
• Whether the complaint arose from trauma or overuse
• Presence of swelling, redness, warmth or restricted movement
• Whether the knee gives way, catches or locks
• Laxity or tenderness in ligament structures
• Muscle strength, gait pattern and range of motion of the knee
• Possibility of pain referred from the hip, ankle or lower back to the knee

Pain severity can be recorded using a scale from 0 to 10 during follow-up. However, this number alone does not establish a diagnosis; it must be interpreted together with examination findings and functional loss. Systematic evaluation of knee pain has been addressed in a 2023 review entitled Evaluation and Treatment of Knee Pain: A Review (PMID 37874571).

Which imaging method is used and when?

The choice of imaging depends on the specific question being answered on examination. Not every case of knee pain requires immediate MRI.

Method	When is it typically evaluated?
X-ray	In suspected fracture, osteoarthritis, joint space narrowing or bone changes
Ultrasound	Assessment of superficial tendons, fluid accumulation and some soft tissue problems
MRI	Detailed evaluation of the menisci, anterior or posterior cruciate ligaments, cartilage and other soft tissues
CT	Cases where complex fractures and detailed imaging of bone structure are required

For example, kneecap pain that worsens when climbing stairs or after prolonged sitting may direct examination towards patellofemoral structures. Conversely, a popping sensation during trauma, rapid swelling and knee giving way may require evaluation for ligament injury.

Why are blood tests or joint fluid analysis requested?

If there is significant warmth, redness, fever or unexplained severe swelling in the knee, evaluation is not limited to imaging alone. Blood tests can help identify inflammation or infection. Where necessary, fluid obtained from the joint can be examined for infection, bleeding or crystal deposition.

Joint fluid sampling is not a routine procedure for every patient; the decision is made based on clinical findings. Results from any surgical or interventional procedure can vary from person to person. Diagnosis is not based on a single test result but on the combined evaluation of history, examination, imaging and, where necessary, laboratory findings.

Treatment Options and When Surgery is Considered?

Surgery becomes relevant in knee pain when diagnosis, tissue damage, knee function and response to non-surgical treatment are considered together. Exercise, physiotherapy, load management and appropriate interventional options form part of treatment. However, in cases of locking, significant instability, progressive joint damage or acute injuries requiring repair, surgical timing is not delayed.

Treatment is not planned solely based on pain severity. Stair climbing, squatting, walking, night sleep and work-related restrictions are evaluated together with examination and imaging findings. For example, pain described as 7 on a 0–10 scale is important, but two people with the same score may have different causes—ligament injury, kneecap pain or osteoarthritis—and thus require different treatments.

Non-surgical options may include, depending on diagnosis:

• Temporary modification of load on the knee and adaptation of movements that aggravate pain
• Personalised exercise to improve muscle strength, joint movement and balance
• Physiotherapy and gradual activity programme
• Where appropriate, bracing, walking aids or similar assistive devices
• Medication or injection options as assessed by the doctor
• Controlled return to sport in cases of pain following overuse

In hip or knee osteoarthritis, physiotherapy is a planned process that addresses movement, strength and functional loss together. This approach is also discussed in A clinical practice guideline for physical therapy in patients with hip or knee osteoarthritis (2020, PMID 32643252). The type and intensity of exercise are determined by the cause of pain, degree of functional loss and any coexisting conditions.

Situations that bring surgery to the fore typically include:

• Recurrent giving way of the knee and loss of confidence in daily movement
• True locking associated with loose bodies within the joint or meniscal damage
• Marked instability associated with complete ligament rupture
• Displaced fracture, trauma affecting the joint surface, or tendon rupture
• Permanent limitation of movement and loss of function accompanied by progressive cartilage loss
• Marked limitation of daily activities despite non-operative treatment carried out for appropriate duration and content
• Suspicion of infection or rapidly deteriorating post-operative condition

Surgical method is determined by diagnosis. Meniscal tears that are repairable may be repaired; ligament injuries may be reconstructed; selected cartilage problems may be managed with joint-preserving procedures. In advanced joint damage, osteotomy or knee replacement options are considered; age, bone structure, deformity, activity expectations, and which areas of the joint are affected are examined together.

Finding a tear on magnetic resonance imaging does not by itself mean surgery is needed. Similarly, finding osteoarthritis on X-ray does not by itself determine the timing of prosthesis. The crucial point is whether the imaging finding supports the same clinical picture as examination, symptoms and functional loss. Evaluation of knee pain and consideration of treatment options within this broader context is examined in the study Evaluation and Treatment of Knee Pain: A Review (2023, PMID 37874571).

With any surgical or interventional procedure, results vary from person to person. Method and timing are determined according to diagnosis, general health status, tissue damage, and personal functional goals.

How to Protect the Knee in Daily Life and When to Return to Exercise

The knee is protected in daily life by temporarily reducing movements that increase pain, gradually increasing load, and performing individualised exercises that strengthen the hip and thigh muscles. Return to exercise should be gradual if there is no significant pain during rest, swelling is not increasing, and knee movement and weight-bearing confidence have returned. In case of new injury or warning signs, assessment is needed first.

How is load managed in daily movements?

Protecting the knee does not mean stopping movement completely. Prolonged immobility may reduce muscle strength; persisting with the same load despite pain can increase complaints. The correct approach is to maintain balance between daily load and the knee's response.

• Rather than staying in the same position for long periods, short movement breaks are taken at regular intervals.
• If squatting, kneeling, and stair use increase kneecap pain, the frequency of these movements is temporarily reduced.
• Stairs are not rushed; if needed, handrail support is used.
• Carried load is distributed evenly between both hands. When lifting a heavy object, the trunk is rotated to avoid sudden loading on the knee.
• Footwear is ensured to be suitable for the ground, balanced, and to provide proper foot support.
• Before exercise, a brief warm-up such as slow-paced walking is performed; exercise intensity is not increased suddenly.

Particularly in patellofemoral pain, that is pain felt around the kneecap or in the front of the knee, control of not just the knee itself but also the hip and thigh muscles is important. Exercise selection is adjusted according to the location of pain, whether there is ligament or meniscal injury, and the person's daily movement needs. This approach is also addressed as one of the fundamental components of individualised exercise in the physical therapy guideline for hip or knee osteoarthritis.
PMID 32643252 — A clinical practice guideline for physical therapy in patients with hip or knee osteoarthritis (2020)

What signs indicate readiness to return to exercise?

The calendar alone is not the measure for return. Two people who have the same injury may recover muscle strength, swelling, and movement control over different timeframes. Before starting or increasing exercise, the following signs are evaluated together:

• No significant pain during rest
• Swelling does not develop or increase after walking
• No significant loss of knee extension and flexion compared to the previous day
• Able to bear weight without limping
• On stairs, sitting down and standing up, and short walks, the knee does not feel as if it will give way
• No significant control difference between the right and left leg
• Complaints do not permanently worsen after exercise

Pain can be recorded on a 0–10 scale before exercise, immediately after, and within the following 24 hours. Here, the change over time is more important than a single number. For example, if mild discomfort during walking becomes worse the next day with swelling, limping, or loss of movement, it suggests the load was increased too quickly.

How is load increase planned?

When returning to exercise, duration, speed, resistance, and repetitions are not all increased at the same time. First, controlled movement on level ground is achieved; then duration is increased, followed by work requiring tempo changes and direction changes.

1. Start with joint movements and muscle activation that do not significantly increase pain.
2. Short, low-tempo walking on level ground is attempted.
3. If the knee responds appropriately, walking duration is gradually increased.
4. In the next phase, controlled sit-to-stand, balance, and strength exercises are added.
5. Running, jumping, and sudden direction changes are considered when swelling-free walking and basic strength exercises can be performed.
6. When returning to sport-specific movements, movement quality and knee control are monitored before speed.

Not every discomfort during exercise means damage. On the other hand, sharp pain, knee giving way, locking, new swelling, or significant restriction of movement are not "go ahead" signs. In such a situation, load is reduced and orthopaedic or physical therapy evaluation is obtained. If unable to bear weight after new injury or if previously described warning signs develop, medical evaluation should be sought before attempting exercise.

Frequently asked questions

When is knee pain dangerous?

If sudden and significant swelling, redness, increased heat, fever, deformity, inability to bear weight, or knee locking accompanies knee pain, it should be evaluated without delay. A popping sound during trauma, knee giving way, or cold and numb foot may suggest ligament, bone, nerve, or blood vessel injury. If isolated leg swelling develops with shortness of breath or chest pain, 112 should be called or emergency services should be sought.

What conditions cause knee pain?

Knee pain can arise from various causes including osteoarthritis, meniscal and ligament injuries, patellofemoral pain, tendon problems, bursitis, rheumatological diseases, and infection. Pain originating from the hip or lower back region may also be referred to the knee. A definitive diagnosis of the cause cannot be made without assessing together the location of pain, how it started, swelling, and movement restriction.

What causes knee pain during pregnancy?

Knee pain in pregnancy is typically associated with increased body weight, changes in posture and gait, and hormonal changes affecting connective tissue. Anterior knee or patellofemoral pain may become more pronounced during stair climbing, prolonged sitting and squatting. If sudden swelling, redness, increased warmth in one leg or calf pain develops, same-day medical evaluation is required; if shortness of breath or chest pain occurs, emergency services should be contacted.

Does knee pain cause fever?

Knee pain itself does not cause fever; however, fever accompanied by a red, hot and swollen knee may indicate infection or inflammation. Particularly if there is a recent history of surgery, injection or open wound, same-day evaluation is required. If there is high fever, chills or general deterioration, emergency department should be visited.

Which department should I visit for knee pain?

Initial evaluation for knee pain is typically conducted at the orthopaedic and trauma department. Depending on examination findings, consultation with physiotherapy and rehabilitation, rheumatology or another specialty may be requested. If there is significant trauma, deformity, inability to bear weight, rapidly increasing swelling or a hot, red knee accompanied by fever, emergency evaluation should be performed without waiting for an outpatient appointment.

Is knee pain occurring with squatting or in young age serious?

Knee pain occurring with squatting or in young age does not always indicate serious damage; it may be related to patellofemoral pain, muscle imbalance, overload and exercise technique. However, if there is knee locking, giving way, significant swelling, history of trauma or loss of movement, examination is necessary. Once the cause of pain is identified, appropriate exercise and load management should be tailored to the individual.

This section is for general information purposes and does not replace medical examination and individualised diagnosis or treatment planning.