Baker's cyst

The main symptom of a Baker's cyst is a soft lump at the back of the knee.

The fluid-filled lump may be more visible when standing up.

The lump may be your only symptom, but you may also have:

• knee or leg pain
• tightness, stiffness or aching in your knee
• difficulty bending your knee
• clicking in your knee

Your symptoms may be worse after walking.

• you have a lump anywhere on your body and you do not know what it is

The GP will examine your leg and check for other health conditions that could be causing a Baker's cyst.

They may send you for an ultrasound or MRI scan, or refer you to a specialist for more tests or to rule out any serious causes.

A Baker's cyst does not always need treatment. Sometimes, particularly in children, it will get better on its own.

If the Baker's cyst is caused by an underlying condition, your symptoms will usually get better when that condition is treated. But other treatments for a Baker's cyst can include:

• painkillers
• a painkilling injection (hydrocortisone injection) in your knee
• physiotherapy
• draining fluid out of the cyst
• surgery to repair damage to your knee joint – it's rare to have surgery to remove a Baker's cyst

A Baker's cyst can take a few months to a few years to get better.

There are things you can do to ease the pain, swelling and other symptoms of a Baker's cyst while it gets better.

They can also help if a Baker's cyst has burst (ruptured). If this happens, your symptoms will be worse than normal until the swelling goes down, which can take a few weeks.

• rest your knee

• gently apply an ice pack (or a bag of frozen vegetables) wrapped in a tea towel to your knee for around 10 minutes at a time, and repeat every few hours if needed

• raise your leg – you can rest it on a pillow

• take ibuprofen or paracetamol to help with pain and swelling

Sometimes there is no particular cause of a Baker's cyst, especially in children.

In adults they usually happen when another health condition causes damage to the knee joint, like:

• a knee injury
• osteoarthritis or rheumatoid arthritis
• gout

Anyone can get a Baker's cyst, but they are more common in people aged 35 to 70.

A Baker's cyst is a lump at the back of the knee. Your knee may be painful, tight, stiff or difficult to bend. Symptoms may be worse after walking.

A Baker's cyst may get better on its own or by treating the condition causing it. Other treatments can include painkillers or physiotherapy.

Rest, ice packs, and ibuprofen or paracetamol can help pain or discomfort caused by a Baker's cyst, especially if it has burst.

There may be no particular cause of a Baker's cyst, but in adults they are usually caused by a knee injury or a condition such as arthritis.