PATIENT EDUCATION
Knee Symptoms
Select the symptom that most closely describes what you are experiencing. The information below explains common causes, possible conditions, initial self-care and when medical assessment may be needed.
Select a symptom below to view more information.
English
தமிழ்
हिन्दी
Pain With Stairs, Kneeling or Squatting
What you'll notice or feel
- Pain going down stairs, often worse than going up.
- Discomfort when kneeling, squatting or rising from a low chair.
- Aching at the front of the knee after sitting with the knee bent for a long time.
- Pain around or behind the kneecap rather than deep inside the joint.
Common causes
- Irritation of the joint surface behind the kneecap.
- Wear of the joint surface, particularly behind the kneecap.
- Weakness or imbalance of the thigh muscles affecting kneecap tracking.
- Overuse after a sudden increase in stairs, kneeling or squatting.
What it could be
- Patellofemoral pain — a common cause of front-of-knee pain.
- Knee osteoarthritis, including wear behind the kneecap.
- Patellar tendon irritation, especially with running or jumping.
- A cartilage or meniscus problem if there is also catching or swelling.
Initial self-care
- Temporarily reduce deep squatting, kneeling and repeated stair use where possible.
- Quadriceps strengthening is often particularly useful for this pattern.
- Avoid prolonged sitting with the knee fully bent.
- Use over-the-counter pain relief if appropriate, as per the label.
When to see a doctor urgently
- Inability to bear weight following an injury.
- Significant swelling developing within hours of an injury.
- Visible deformity or complete giving way after a specific injury.
When to see a doctor
- Pain persisting beyond 4–6 weeks despite activity modification and strengthening.
- Pain limiting work, stairs or daily independence.
- Pain repeatedly returning with the same activities.
Swelling
What you'll notice or feel
- Visible puffiness around the knee.
- A sense of tightness or fullness, particularly when bending.
- Swelling developing quickly after injury or gradually without a clear cause.
- Reduced ability to fully bend or straighten because of the swelling.
Common causes
- Fluid produced within the joint in response to irritation, wear or injury.
- Bleeding into the joint following a significant injury.
- An inflammatory joint condition.
- Infection if the knee is hot, red and increasingly painful.
What it could be
- Joint fluid associated with osteoarthritis or general joint irritation.
- Bleeding into the joint after ligament or cartilage injury.
- An inflammatory or crystal-related condition such as gout.
- An infected joint, which requires urgent treatment.
- A Baker's cyst behind the knee, often secondary to another joint problem.
Initial self-care
- Rest, ice and elevation while acute swelling settles.
- Gentle movement within a comfortable range.
- Use over-the-counter pain relief if appropriate, as per the label.
- Note how quickly the swelling appeared — this is useful diagnostic information.
When to see a doctor urgently
- The knee is hot, red and increasingly painful, or you have fever.
- Swelling developed within hours of an injury.
- Inability to bear weight alongside the swelling.
- Sudden severe pain with swelling behind the knee, especially with calf swelling.
When to see a doctor
- Swelling persisting beyond 1–2 weeks.
- Swelling that recurs repeatedly.
- Swelling without a clear cause or injury.
Instability / Giving Way
What you'll notice or feel
- A feeling that the knee may buckle or give way, especially while turning or walking on uneven ground.
- Episodes where the knee actually gives way.
- Reduced confidence in the knee, leading to avoidance of certain activities.
- Sometimes a history of a twisting injury or a felt/heard pop.
Common causes
- A ligament injury, particularly one affecting rotational stability.
- Weakness of the thigh muscles.
- A cartilage tear causing catching and momentary giving way.
- Kneecap instability or partial dislocation.
What it could be
- An anterior cruciate ligament (ACL) tear.
- Muscle weakness creating a sense of instability without structural damage.
- A meniscus tear causing catching and giving way.
- Patellar instability or previous partial kneecap dislocation.
Initial self-care
- Avoid pivoting, twisting and uneven ground until assessed.
- Thigh muscle strengthening can improve stability in many cases.
- A supportive knee brace may help confidence during activity.
- Avoid returning to sport before proper assessment if a ligament injury is suspected.
When to see a doctor urgently
- Giving way immediately after a significant injury, particularly with rapid swelling.
- Inability to bear weight.
- A knee locked in a bent position that cannot be straightened.
When to see a doctor
- Recurrent giving way or persistent instability.
- Instability limiting activity or confidence.
- A previous knee injury with ongoing instability.
Locking or Catching
What you'll notice or feel
- The knee getting stuck momentarily during movement.
- A catching sensation at a particular point in the range of motion.
- True locking, where the knee cannot be fully straightened.
- Sometimes pain along the joint line.
Common causes
- A torn piece of meniscal cartilage getting caught between the joint surfaces.
- A loose fragment of cartilage or bone within the joint.
- Wear-related irregularities of the joint surface.
- Pain-related guarding that feels like locking without a true mechanical block.
What it could be
- A meniscus tear — a classic cause of true mechanical locking.
- A loose body within the joint.
- Wear-related joint surface irregularity.
- Pseudo-locking caused by pain or muscle spasm.
Initial self-care
- Avoid deep squatting and twisting movements.
- Use gentle range-of-motion exercises within a comfortable range.
- Use over-the-counter pain relief if appropriate, as per the label.
- Note whether the knee truly cannot straighten, or whether it is simply painful to straighten.
When to see a doctor urgently
- The knee is locked and cannot be straightened at all.
- Locking following an acute injury with significant swelling.
- Inability to bear weight.
When to see a doctor
- Recurrent catching or locking episodes.
- Catching that limits activity.
- Catching alongside joint-line pain or recurrent swelling.
Stiffness
What you'll notice or feel
- Difficulty fully bending or straightening the knee.
- Stiffness that is worse after rest or first thing in the morning and eases with movement.
- A feeling that the knee needs to warm up before moving freely.
- Reduced ability to squat, kneel or climb stairs.
Common causes
- Wear of the joint surface.
- An inflammatory joint condition.
- Stiffness following previous injury, surgery or immobilisation.
- Swelling within the joint mechanically restricting movement.
What it could be
- Knee osteoarthritis.
- An inflammatory joint condition, particularly when morning stiffness is prolonged.
- Post-operative or post-immobilisation stiffness.
- Restricted movement secondary to fluid within the joint.
Initial self-care
- Regular gentle range-of-motion exercises, especially working toward full straightening.
- Heat before activity to ease stiffness.
- Avoid prolonged periods of immobility.
- Maintain thigh muscle strength to support the joint.
When to see a doctor urgently
- Sudden marked loss of movement, especially with severe pain or swelling.
- Stiffness associated with fever, redness and warmth.
- Stiffness following a significant injury.
When to see a doctor
- Stiffness persisting beyond a few weeks and limiting daily activities.
- Morning stiffness lasting well over half an hour, especially if other joints are also affected.
- Progressive loss of the ability to fully straighten the knee.
YOUR CONSULTATION
What to Expect at Your Visit
- The doctor will ask where the pain is, whether there was a specific injury, how quickly any swelling appeared and whether the knee locks or gives way.
- You'll be examined for knee movement, swelling, joint-line tenderness, thigh muscle strength and walking pattern, together with specific tests for ligament stability and cartilage injury.
- Your hip may also be examined because hip problems can sometimes refer pain to the knee, especially in children and adolescents.
- Imaging usually starts with a weight-bearing X-ray. MRI may be added when a ligament, meniscus or other soft-tissue injury is suspected.
- Joint fluid may occasionally be drawn off and tested if infection or a crystal-related condition is being considered.
- Management may include physiotherapy, strengthening, activity modification, weight management and injections. Surgical treatment may be discussed where appropriate, ranging from keyhole procedures for selected mechanical problems to joint replacement for advanced wear.
* IMPORTANT: A Note Before You Go
Hip symptoms can sometimes be felt in the groin, thigh, knee or lower back, which means the location of pain does not always identify the source on its own.
This page covers some of the more common reasons for knee symptoms and is not a complete list of everything that can affect the hip. It cannot replace an individual medical assessment. If your symptoms are persistent, worsening or affecting walking, sleep or normal daily activities, it is appropriate to have them assessed.