Back of knee pain is a discomfort that occurs behind your knee joint. This soreness may occur either at rest or during movement and may even limit movement when severe. Back of knee pain may also be described variously as a soreness, discomfort, burning pain, inflammation, stiffness, or increased warmth.

Causes and Treatments of Back of Knee Pain

There are many possible causes of back of knee pain, and their treatment depends on the diagnosis:

1. Baker's Cyst

A bulging cyst that is fluid-filled and gives a feeling of tightness behind the knee may be due to a Baker's cyst. Because of its location, the cyst, also called popliteal cyst, can result in discomfort and pain especially during activity, when the knee is extended or flexed. The cause is usually related to a knee joint problem, such as arthritis or torn cartilage, which results in fluid accumulation. Other symptoms include stiffness and swelling at the back of the knee.

A physical examination usually leads to the diagnosis, but the doctor may order other tests like ultrasound or MRI to rule out other conditions, such as an aneurysm, a blood clot, or a tumor.

No treatment is necessary because a Baker's cyst often disappears on its own. However, if it is too large and painful the doctor may give you a local corticosteroid injection or drain fluid from your knee using a needle under guidance with an ultrasound. Physical therapies like using ice, compression wraps, or crutches may also help reduce swelling and pain. Strengthening and range-of-motion knee exercises may also help relief symptoms and preserve your knee function.

2. Osteoarthritis

Osteoarthritis is a common condition that affects millions of people globally. It occurs when the cartilage at the ends of the bones are damaged or worn down in time. Older people, women, and people who have bone deformities or joint injuries have an increased risk for osteoarthritis. Other risk factors include obesity, occupational factors, and other diseases, which may also increase one's likelihood of developing osteoarthritis. The disorder commonly affects joints of the neck, hands, lower back, hip, and knees. Symptoms of arthritis of the knee include joint pain, tenderness, stiffness, limitation of motion, and grating sensation.

The diagnosis of osteoarthritis may be made from medical history, physical examination and imaging exams such as x-ray and MRI. Treatment includes rest, the use of nonsteroidal anti-inflammatory drugs (NSAIDs), steroid injections, and physical and occupational therapy. Some people may need surgery, such as joint realignment (osteotomy) or joint replacement.

3. Rheumatoid Arthritis

This form of arthritis is an autoimmune disorder that causes chronic inflammation of the small joints in the hands and feet. Rheumatoid arthritis causes a painful swelling of the lining of the small joints resulting in erosion of the bones and joint deformity.

Other symptoms include fever, fatigue, morning stiffness, weight loss, and formation of nodules (bumps) under the skin. Rheumatoid arthritis is common in women and generally occurs between ages 40 to 60.

Diagnosis is made from medical history, physical examination, blood tests, and x-rays. Treatment is aimed at controlling your symptoms and preventing further joint damage. These include taking NSAIDS, steroids, immunosuppressants and other drugs to control inflammation and pain. Other treatments include physical therapy, use of assistive devices, and surgery. Home remedies such as regular exercise, heat and cold application, and relaxation are also recommended.

4. Torn Ligament or Cartilage

A torn knee ligament or cartilage is a common injury from contact sports or other types of accidents. Factors that contribute to back of knee pain due to injuries are aging, excessive pressure on the knee and normal wear and tear. Symptoms include knee swelling, pain while walking, and joint locking.

Diagnosis is made from medical history, physical examination and imaging exams. Treatment begins with resting, applying ice, compression of the knee joint and elevation of the affected leg.

Surgery may be needed in case of severely torn ligament or cartilage. Physiotherapy using range- of-motion knee exercises can help strengthen the joint.

5. Torn Hamstring Muscle

Another type of injury that can cause back of knee pain is the "pulled hamstring," which is common among athletes engaged in sprinting, basketball, and soccer. This involves a strain or injury to the muscles at the back of your thigh. Other risk factors include muscle tightness, muscle imbalance, poor conditioning and muscle fatigue. Symptoms include a sudden pain that is sharp at the back of the thigh, which can cause you to stop and fall or hop on your good leg. Swelling, bruising, discoloration at the back of the leg and weakness of the leg may also occur.

Diagnosis is made from medical history, physical examination and imaging exams. Treatment consists of resting, applying ice, compression of the leg muscles and elevation of the affected leg.

Surgery may be needed in case of severely injured muscles. Physiotherapy using strengthening and range-of-motion exercises can help strengthen the muscles.

6. Deep Vein Thrombosis

A blood clot that forms in one of the large veins in the leg is a deep vein thrombosis (DVT) that can cause back of knee pain. This can happen at any age but it is more common among people over 60 years of age. Other risk factors include prolonged bed rest, recent surgery, obesity, cancer, smoking, intake of birth control pills, and fractures. You will note a change in color of the leg, which occurs with pain, increase in warmth of the leg, and swelling.

The two diagnostic tests that are often needed to diagnose a DVT are the D-dimer blood test and a Doppler ultrasound exam of the affected leg. Other blood tests to determine increased tendency to clot may be ordered. Treatment involves using anticoagulants, which thin the blood to prevent further clotting, putting on pressure stocking to improve blood flow in the legs, and rarely, surgery.

7. Peripheral Artery Disease (PAD)

This is a common problem involving the impaired circulation in narrowed arteries in the legs, which results in leg pain especially when walking. This condition is caused by the accumulation of fatty deposits in the arteries, leading to reduction of blood flow to your legs. Risk factors include smoking, diabetes, obesity, high blood pressure, high cholesterol, and family history of PAD. The most common symptom is cramping or pain in the lower leg (calf) muscles during walking, which disappears with resting. Other symptoms include change in the color of the leg, hairless legs, numbness, cold leg temperature, and erection problems in men.

Diagnosis can be confirmed using a Doppler ultrasound and other imaging exams using angiography. Treatment includes medications to control blood sugar, blood cholesterol, high blood pressure and prevent blood clots. Angioplasty and surgery may be needed to remove the blood clots in severe cases.

8. Other Causes

Aside from specific conditions that can lead to back of knee pain, there are other factors that can cause this, such as:

• Overweight or obesity, where the extra weight of the upper body exerts added stress on the front and back portions of the knee, leading to pain.
• Overuse of knees, especially in people who are involved in sports like running and cycling, which exerts excessive stress on the knees, leading to pain
• Another conditionwhere the kneecap rubs on the lower end of the thigh bone instead of gliding over it. This causes friction and intensifies the pain.

Complications of Back of Knee Pain

Back of knee pain may be a symptom of a serious disorder and failure to get appropriate treatment can lead to complications. You need to seek help from your health care provider if you experience persistent back of knee pain, leg pain, redness, increased warmth, and other unusual symptoms. Potential complications include disability, loss of mobility, and poor quality of life due to persistent pain. Serious complications include pulmonary embolism, which is life threatening. This often results from deep vein thromboembolism (DVT). Seek immediate help (call 911) if you experience chest pain, difficulty breathing, blood in spit, fainting and loss of consciousness.