The most common cause of chronic calf pain is a muscle injury, which can cause inflammation, strains, or tearing in any of the three major muscles of the calf. An injury to those muscles can in turn cause other injuries, causing chronic, recurring calf pain. Tendinitis — or swelling of a tendon — is another common cause of chronic calf pain, as are cramps common during physical activity. More serious causes of chronic pain in the calves may include cysts in or around the muscles of the calf, and blood clots, which is a condition that will require medical attention.
A calf strain occurs when too much force is applied to the calf muscles. The muscles are not prepared to handle the load, and they can contract beyond their normal capacities. A muscle strain causes a dull ache, soreness, tenderness, and general weakness in the calf area. It is usually treated with the RICE system — Rest, Ice, Compression, Elevation — as well as light stretching and exercise after several days of rest. Medical attention is usually not necessary for treatment of a calf strain, though some more serious strains may require physical therapy. A more serious muscle tear will require significantly more rest and attention as the muscle reattaches itself. In some severe cases, the muscle may need to be repaired surgically.
Chronic calf pain may also result from muscle cramps or overuse. Runners will often get chronic calf pain after running too far, especially if the runner's shoes are old, worn out, or not supportive enough. Corrective footwear or new running shoes may solve the problem, as will sufficient rest between running activities. Cramps can be caused by dehydration or overuse of the muscle, as well as by lactic acid build-up in the muscles, and a runner or other athlete should be sure to drink plenty of fluids before, during, and after exercise.
More serious conditions that can cause chronic calf pain include cysts and blood clots. If the pain is not the result of an injury or persistent exercise, a blood clot may be the cause. The clot restricts blood flow through the calf, and swelling and pain usually accompanies the presence of a clot. If pain persists after a surgery, beginning of a medication regimen, or other practice out of the ordinary, one should consult a doctor immediately. If the pain is behind the knee, a Baker's cyst may be the culprit; this cyst is caused by fluid collecting above the calf muscles. The fluid will have to be drained to alleviate the pain.