Knee pain

How to ease knee pain and swelling

To help ease knee pain and swelling you could try:

• putting as little weight as possible on the knee – for example, avoid standing for a long time
• using an ice pack (or bag of frozen peas wrapped in a tea towel) on your knee for up to 20 minutes every 2 to 3 hours
• taking painkillers such as paracetamol or ibuprofen

When to see your GP

You should see your GP if you have knee pain and: 

• it doesn't improve within a few weeks
• you can't move your knee or put any weight on it
• your knee locks, painfully clicks or gives way – painless clicking is normal
• unexplained weight loss
• pain at night or at rest
• you have previously been treated for cancer

When to get immediate medical help

You should go to your nearest emergency department if:

• your knee is very painful or the pain starts suddenly
• your knee is badly swollen or has changed shape
• you have a very high temperature, feel hot and shivery, and have redness or heat around the knee – this can be a sign of infection

Common causes of knee pain

Knee pain can be a symptom of many different conditions. Your doctor will suggest treatment based on the condition causing your pain. They might:

• refer you to hospital for a scan or specialist treatment, for example, surgery
• prescribe medication or physiotherapy

Knee pain after an injury

Below are some common causes of knee pain. The information may help you but don’t rely on it for a diagnosis – see a GP if you are concerned about your symptoms.

Sprains and strains

Sprains and strains can lead to knee pain after overstretching, overusing or twisting.

Tendonitis

Tendonitis can lead to pain between your kneecap and shin – this is often caused by repetitive running or jumping.

Torn ligament, tendon or meniscus and cartilage damage

Torn ligament, tendon or meniscus and cartilage damage can lead to your knee:

• being unstable
• giving way when you try to stand
• being unable to straighten

You may also hear a popping sound during the injury.

Dislocated kneecap

A dislocated kneecap can lead to changes in shape to the knee after a collision or sudden change in direction.

Knee pain with no obvious injury

Below are some common causes of knee pain with no obvious injury. But don't self-diagnose – see a GP if you're worried.

Osteoarthritis

Osteoarthritis can lead to pain and stiffness in both knees, mild swelling – it is more common in older people

Bursitis

Bursitis is when your joints become painful, tender and swollen. It can affect any joint but is most common in the shoulders, hips, elbows or knees.

Bleeding in the joint

Bleeding in the joint can lead to swelling, warmth and bruising – it is more likely while taking anticoagulants

Gout or septic arthritis

Gout or septic arthritis can lead to the knee becoming hot and red with sudden attacks of very bad pain.

Osgood-Schlatter's disease

Osgood-Schlatter's disease can lead to pain and swelling below the kneecap in teenagers and young adults.

Baker's Cyst

A Baker's cyst, also called a popliteal cyst, is a fluid-filled swelling that develops at the back of the knee. It's caused when the tissue behind the knee joint becomes swollen and inflamed.

The swelling and inflammation can cause:

• pain in the knee and calf

• a build-up of fluid around the knee

• occasional locking or clicking in the knee joint

Osteochondritis dissecans (OD)

Osteochondritis dissecans (OD) is a joint disorder in which cracks form in the cartilage in the knee joint. OD causes pain and swelling of the joint which catches and locks during movement. Reduced blood circulation to the bone causes fragments to break off into the joint space causing symptoms. It generally affects growing adolescents, but can affect adults.

'Growing pains'

Growing pains are aches or pains, usually in the lower legs, that develop in the evening or night. Children aged between three and 12 may be affected. Although they can be distressing, growing pains are fairly common and don't cause long-term harm.

Referred pain

Pain caused by a problem in the hip joint can be felt in the groin, down the front of the leg and in the knee. Sometimes knee pain is the only sign of a hip problem. This is called referred pain, and it’s fairly common. 

• Read more about hip problems

More useful links

• How to use your health services