Knee Pain

Is this your symptom?

• Pain in the knee
• Includes minor muscle strain from overuse
• If pain is caused by an injury, see Knee Injury care guide

Causes of Knee Pain

• Muscle Overuse(strained muscles). Knee pains are often from hard muscle work or sports. Examples are too much walking or running. This type of pain can last from hours up to 7 days.
• Muscle Cramps. Brief pains that last 1 to 15 minutes are often due to muscle cramps. These often occur in the calf or feet at night. They can also occur in the hamstrings at the back of the knee and thigh.
• Trapped Nerves. The nerves in the lower leg can become trapped or squeezed where they pass through narrow spaces as they leave the spine. Sciatica is from pressure on a nerve in the back. It causes tingling, weakness or pain in the leg which may go right down to the toes. You may feel pain from a trapped nerve in your knee. If symptoms do not go away with rest or treatment, surgery may be needed to release the nerve.
• Viral Illness. Mild muscle aches in both legs or in the joints also occur with many viral illnesses, such as flu.
• Septic Arthritis (serious). This is a bacterial infection of a joint space. Main symptoms are fever and severe pain when you move the joint. It may not be possible to move the joint at all. This needs care right away.
• Joint Inflammation. Examples are rheumatoid arthritis, osteoarthritis and gout. Some, like gout, may affect just one joint. Others affect multiple joints at the same time. Early treatment may help prevent long-term damage to the joints involved.
• Bursitis. Many joints, like the knee, are covered by fluid-filled sacs called bursae. They help the joint move smoothly. These bursae can get inflamed or infected, causing pain and swelling. The bursa at the front of the knee, over the knee-cap, can become inflamed from too much kneeling and knee bending. The area may look red and feel warm to touch.
• Referred pain. Pain is sometimes felt in the knee when there is not actually a problem with the knee itself. This is called referred pain. Problems like arthritis in the hip can lead to pain being felt in the knee.
• More serious causes of knee pain:
• Bone cancer or bone infection (osteomyelitis). Fractures can happen during normal activity without an injury. Do not ignore ongoing leg pain.
• Clots in the veins of the leg can cause pain and itching if they occur in veins near the surface of the skin. If clots occur in the deeper, bigger veins in the legs, it can be life-threatening. Pain may be felt behind the knee. Pieces of the clot can break off and travel to the heart and lungs. If this happens, it can cause breathlessness or chest pain.
• Blockage of an artery. Arteries carry oxygen from your heart to the leg tissues. Symptoms of blockage are cold, pale and numb and/or painful leg. The blockage will need to be cleared as an emergency when this happens. Partial blockage can cause pain, often in the calf or behind the knee, when walking. The pain will usually go away when at rest but may need treatment before the artery becomes completely blocked.

Pain Scale

• Mild: you feel some pain, but it does not keep you from any normal activities. Work, chores and sleep are not changed.
• Moderate: the pain keeps you from doing some normal activities. It may wake you up from sleep.
• Severe: the pain is very bad. It keeps you from doing all normal activities.