The accumulation of synovial fluids or the joint fluid results in the formation of a Baker's cyst behind the knee. Sometimes, a Baker's cyst at the back of the knee disappears on its own and gives no long term side effects. But, they can cause discomfort and pain to a person. Here is more information about the causes, symptoms, and treatment of the Bakers' cyst behind the knee.

The formation of this cyst is not a very serious health problem. A Baker's cyst in most people goes away on its own. However, if the cyst stays for long, it can cause considerable discomfort to a person. This cyst can also create problems, if it gets ruptured. A ruptured cyst will cause pain, swelling, and bruising in the affected part. If you have a lump behind your knee region, it is most probably a Baker's cyst which needs to be checked by a medical practitioner.

Causes
Here is a list of the possible causes

• Trauma or injury during a sport or accident causes the building up of joint fluid
• Arthritis, both rheumatoid arthritis and osteoarthritis
• It is more common in children for no apparent reason
• Infection behind the knee can lead to fluid retention and trigger the cyst
• A torn cartilage

Symptoms
Baker's cyst on knee generally doesn't have any symptoms, however the common symptoms that may occur are -

• The cyst when touched, feels like a water filled balloon.
• Restricted movement of the knee joint.
• A feeling of pressure at the back of the affected knee.
• Lump is more visible on the knee, when the person is standing.
• If the cyst ruptures, then a person might experience pain and swelling.
• A person with a ruptured cyst will also experience bruising on the back of knee and the calf.

Treatment
Here is the information about the diagnosis and treatment of the cyst and the complications which can arise if it is left untreated.

Diagnosis: The doctor will perform a physical examination of the cyst at the back of your knee. Shining a light through the lump can show if the lump is filled with liquid and if it is a cyst. Other exams and tests which are performed for diagnosing cysts include X-ray, MRI scans, and ultrasound.

Treatment: There is often no treatment required for Baker's cyst, the doctor observes the cyst over time. The treatment is aimed at treating the underlying cause, rather than the symptoms. The treatment involves - medicines for arthritis, physical therapy like using ice packs and performing exercises, and draining the cyst by using a needle. In some cases, cortisone injections are used and in severe cases the cyst is removed by surgery.

Complications: If a Baker's cyst is left untreated then certain complications can arise. The first complication is the rupturing of the cyst that can cause pain, swelling, and bruising of the affected area. The symptoms can become worse as the cyst grows in size. The cyst can enlarge and grow towards the calf muscles.

If you feel the presence of a lump behind your knee get it checked by a doctor. The doctor might recommend treatment in certain cases, but in most cases the cyst will disappear on its own without causing much discomfort to you.

Disclaimer: This Buzzle article is for informative purposes only, and should not be used as a replacement for expert medical advice.