Causes of Knee Pain

There are a huge number of causes of knee pain. Sometimes pain comes on after an injury, other times pain in the knee gradually builds up over time with no obvious cause.

To get rid of the pain permanently, it is vital to correctly identify the "cause" (what made it go wrong in the first place), not just the "symptom" (what we feel) otherwise it's likely the problem will come back. 

Let me give you an example. Say your knee is swollen and painful, you could treat that with PRICE, medication and some gentle exercises. The swelling and pain might settle temporarily (i.e. the symptoms go away), but what caused it in the first place is still there in the background. Treatment will certainly help, but as soon as you go back to doing your normal activities, your knee will most likely start hurting again and may swell. However, if you treat the weakness and tightness, you treat the “causes” of knee pain, and hey presto, problem solved.

Common Causes of Knee Pain

Here we will look at the most common causes of knee pain that develop gradually over time, often with no obvious cause.  Problems that are the result of an injury, such as cartilage tears and ligament sprains are covered separately in knee injuries section.

1) Runners Knee

This is one of the most common causes of knee pain around the front of the knee due to a problem with how the kneecap moves. Don’t be fooled by the name. It is just as likely to affect those with sedentary lifestyles as it is active people.

Runners knee is one of the most common causes of knee pai

Causes: There are a number of causes including muscle weakness, tightness, flat feet and hip angle

Symptoms: The most common symptoms are pain over the kneecap, swelling and pain on stairs, especially on the way down. It usually settles within a few months

Treatment: One of the most effective treatments is exercise to strengthen and stretch the knee muscles.  Other things that can help include ice, knee braces and orthotics.  Occasionally surgery is required

Find out more: Runners Knee

2) Chondromalacia Patella

This is one of the most common causes of knee pain in sporty adolescents and young adults, especially females.

Causes: It is caused by damage to the cartilage that lines the back of the knee cap usually due to a combination of muscle imbalance, altered biomechanics and overuse

Symptoms: It results in pain at the front of the knee, especially when going down stairs, or after sitting for long periods, and can cause the knee to make funny noises when it moves.

Treatment: Exercises, knee straps, medication, shoe insoles and activity modification are the usual treatment options with this 

Find Out More: Chondromalacia Patella

3) Osgood Schlatters

This is one of the most common causes of knee pain in teenagers, especially males.

Osgood schlatters Disease is on of the most common causes of knee pain in teenager

Causes: It usually develops after a growth spurt due to the bones growing faster than the muscles, causing friction. This can lead to a bony lump forming just below the patella.

Symptoms: There is usually pain below the kneecap, worse with activity, better with rest.  Tenderness and swelling over the bone are common

Treatment: A combination of PRICE, exercises, knee straps and knee pads usually work well

Recovery: This is one of the longer lasting causes of knee pain and it can take anywhere from a few weeks to 2 years to settle.

Find out more: Osgood-Schlatters-Disease

4) Arthritis

This is the most common of the causes of knee pain in people over the age of 50.

Arthritis is one of the most common causes of knee pain in the over 50's

Causes: It is caused by wear and tear to the cartilage that lines the joint, leading to bone on bone contact. It is more common in women and in those who have previously injured their knee or had knee surgery

Symptoms: Arthritis can cause pain, swelling, weakness, limited movement and difficulty with everyday activities such as walking and going up and down stairs. Symptoms tend to get progressively worse over time 

Treatment: Treatment varies according to the severity of the disease. Common treatments for arthritis include exercises, knee braces, natural remedies, acupuncture, dietary changes, medication and in severe cases surgery

Find Out More: Arthritis

5) Bursitis of the Knee

This is caused by inflammation of a bursa - small fluid filled sacs that lie between bones and muscles/tendons to prevent irritation. There are approximately 15 bursa around the knee.

Inflammation of one of the knee bursa can cause pain

Causes: Excessive friction from activities such as jumping, running or muscle tightness can lead to swelling of one or more bursa which leads to pain.

Symptoms: The location of the pain will depend on which bursa is affected. The symptoms tend to be general pain and swelling around the knee.

Treatment: Rest from aggravating activities is vital when bursitis causes knee pain.  A combination of strengthening and stretching exercises usually helps

Find Out More: Bursitis

6) Bakers Cyst aka Popliteal Bursitis

This is one of the most common causes of knee pain at the back of the knee, and is due to inflammation of the popliteal bursa which sits behind the knee joint.

A Bakers Cyst is one of the most common causes of knee pain behind the knee.

Causes: It is usually caused by fluid associated with arthritis or a cartilage tear leaking into the bursa and causing it to swell, but it can occur after any damage to the knee.

Symptoms: The symptoms tend to be pain and swelling behind the knee, like a soft orange which can limit knee movement.

Treatment: Treatment options include ice, medication and injections to reduce pain and swelling, and exercises.  In severe cases surgery may be necessary

Find Out More: Bakers Cyst

7) Housemaids Knee aka Prepatellar Bursitis

Again, don’t be fooled by the name. Nowadays, it is usually tradesmen such as roofers and carpet layers who spend long periods kneeling who  suffer from this.

Housemaids knee causes swelling at the front of the knee joint

Causes: Excessive kneeling, or less commonly, a knock to the front of the knee causes swelling in the prepatellar bursa.

Symptoms: The most common symptoms are pain at the front of the knee, swelling (again like a soft orange) and difficulty walking, bending the knee and kneeling.

Treatment: As with other bursitis causes of knee pain a combination or rest, ice, medication, injections and exercises tends to be most effective

Find Out More: Housemaids Knee

8) Pes Anserine Bursitis

This is one of the causes of knee pain on the inner side of the knee slightly below the joint, caused by inflammation of the pes anserinus bursa.

Pes Anserine is one of the less common causes of knee pain.  It causes pain on the inner side of the knee, below the joint

Causes: Repetitive friction from activities such as swimming and running irritates the bursa.  People with other medical conditions such as arthritis and type 2 diabetes, along with obese middle aged women are the most likely to be affected

Symptoms: Pain in the inner side of the knee 2-3 inches below the joint in the most defining symptom.  Sleep is often disturbed and there may be weakness and stiffness in the knee

Treatment:  As with most causes of knee pain, exercises are one of the most important treatment options.  They should be used carefully to allow rest from any aggravating activities.  Medication and steroid injections can also help

Find out more: Pes Anserine Bursitis

8) Gout

Gout is a type of arthritis and is one if the causes of knee pain that can affect other areas as well such as the hands and feet.  High levels of urate crystals form in the joint causing inflammation.

Gout causes swelling and redness in the affected joint and can be extremely painful

Causes: Common causes include diet, obesity, genetics, medical conditions such as diabetes and knee injuries

Symptoms:  Gout sufferers typically present with a hot, swollen, red knee which usually develop over night and can be extremely painful

Treatment: Medication is one of the best treatments for inflammatory causes of knee pain and gout is no exception.  Rest and ice can also help

Find out more: Gout Knee

8) Jumpers Knee aka Patellar Tendonitis

This is one of the common causes of knee pain affecting sports players caused by damage to the tendon just below the kneecap.

Patellar Tendonitis is one of the common causes of knee pain below the kneecap

Causes: Repetitive jumping and/or kicking as these activities place lots of strain on the patellar tendon  and can lead to small tears in the tendon. This weakens the tendon and makes it prone to further damage

Symptoms: The most common symptoms include pain just below the kneecap, especially after prolonged periods of rest and/or activity as well as knee stiffness first thing in the morning

Treatment: Rest from any activities that are causes of knee pain here, exercises and in some cases surgery.  Many people find wearing a knee strap really helps as it takes the tension off the tendon

Find Out More: Patellar Tendonitis

9) Iliotibial Band Syndrome aka ITBS

This is the most common of the causes of knee pain on the outer (lateral) side of the joint, and is often seen in runners. The iliotibial band runs down the outer side of the thigh attaching at the knee.

Iliotibial band syndrome typically causes pain on the outer side of the knee

Causes: Excessive friction on the band, caused by things such as muscle imbalance, excessive running, or running on a slope and incorrect training methods result in inflammation of the band

Symptoms: It typically results in pain on the outer side of the knee that gets worse with activities such as running and going down stairs. There may be a funny snapping sensation as you bend your knee and some swelling

Treatment: Rest from aggravating activities is important and should be combined with tailored strengthening and stretching exercises.  Wearing a knee strap can make a big difference along with orthotics, injections and in some cases surgery

Find Out More: Iliotibial Band Syndrome

10) Osteochondritis Dissecans

This is one of the less common causes of knee pain. A reduced blood supply to parts of the bone cause loose fragments of cartilage and bone  to break off. Whilst it can occur in any joint, it is the knee that is the most commonly affected.

Osteochondritis Dissecans is one of the less common causes of knee pain

Causes: Repetitive minor damage to the joint from activities such as jumping and kicking.  There is also thought to be a genetic link

Symptoms: As well as pain, it can cause locking and clunking sensations in the knee, limited movement and swelling

Treatment: Non-surgical treatment includes rest, physical therapy and the use of knee braces.  In some cases surgery is necessary

Find Out More: Osteochondritis Dissecans

To find out more about these common causes of knee pain, including how to treat each one, go back and click the links above.

Want to Know More?

These are the most common causes of knee pain that comes on gradually without an injury. If your pain started due to a one-off injury such as a fall or sporting accident, check out the Common Injuries section for more information on things such as ligament injuries and cartilage tears.

If you're not sure which of these might be your problem, visit the diagnosing knee pain section for a more in depth guide and help working out what might be going on.

If you are looking for more general treatment ideas for your pain, visit the knee treatment section for advice on strengthening exercises, stretches, different types of surgery, and PRICE (protect, rest, ice, compression, elevation) for different causes of knee pain.

Remember, you should always consult a health professional who is trained in diagnosing causes of knee pain, such a doctor or physical therapist with any new onset of pain.

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