What Is the Cause of Calf Pain in Just One Leg?

The possible causes vary depending on the situation in which the pain appeared and other symptoms accompanying the pain.

When sudden pain begins due to sports-related injuries.

In many cases, a sudden burst of movement like dashing to a sprint or diving for a ball can put added stress on the muscles and tendons of the leg. Two common injuries include a strain or tear of either the calf muscle (gastrocnemius) or Achilles tendon due to the sudden stress on that structure. If the pain is severe enough to make walking difficult, consider seeking further medical care along with rest, ice, compression and elevation of that limb.

If you feel numbness along with foot pain

Conditions such as lumbar disc herniation and lumbar spinal stenosis can cause these symptoms because of nerve compression. In particular, nerve pain observed along the back of the thigh to the calf is referred to as "sciatica." In some instances, there may be no back pain.

Without any trigger, sudden pain or swelling suddenly develops

A blood clot (deep vein thrombosis) may form in the larger veins deep in the leg as they traverse the calf muscles. The blockage of the vein leads to pain, swelling and redness of sudden onset. Often times these clots occur after periods of immobility (ie: long plane rides, hospitalization), recent trauma (ie: broken bone or injury to the leg) or other periods of inflammation (ie: critical illness, surgery, cancer). When a blood clot forms in the leg, there is a risk the blood vessel may travel through your blood vessels to the lungs and lead to problems breathing. If you suspect a deep vein thrombosis, seek further medical evaluation.

If there is redness or blisters on the skin of the feet

Redness, pain, blistering and swelling in one calf or leg may also be signs of a bacterial skin infection known as cellulitis. Antibiotics are needed to treat this condition.