The calf and thigh muscles provide over half of the power required to walk, run and jump. They are the muscles that support the knee joint, the largest weight bearing joint in the body. When a person experiences pain in the calf or thigh muscle they have difficulty walking or performing any recreational activity that uses the lower extremities. There can be a variety of reasons for pain and discomfort but treatment cannot begin until the reason has been identified.
Deep Vein Thrombosis
A deep vein thrombosis is a blood clot in a major vein of the lower leg and sometimes the pelvis. These clots can cause swelling in the lower extremity that is affected, as well as pain and discomfort with movement. They may be a result of prolonged bed rest or immobility of the legs. The U.S. National Library of Medicine lists deep vein thrombosis as a reason for pain in either the calf or the thigh muscle.
Varicose Veins
Varicose veins are veins that have become enlarged, twisted and engorged with blood. Veins are the blood vessels that transport the blood from the extremities back to the heart. Inside the veins are valves that keep the blood from flowing in the wrong direction. When those valves become damaged the blood begins to pool, causing permanent damage to the veins. According to the U.S. National Library of Medicine, varicose veins will cause pain and discomfort in the area of the legs that are affected.
Peripheral Artery Disease
The lining of the arteries are usually smooth, but with arterial disease there is a buildup of cholesterol and fats that cause the lining to become rough and thickened. This hardening of the arteries decreases the amount of oxygen that is able to be delivered to the cells of the leg muscles. Lack of oxygen and nutrients leads to cramps and pain in the thighs, hips and calves called claudication. The University of Southern California warns that this peripheral arterial disease is a warning that similar damage may be forming in the arteries that supply the brain and heart.
Compartment Syndrome
This is a cascading event that begins with swelling in tissue after an injury. If swelling develops within an enclosed compartment of fascia, there is very little room for expansion. The Merck Manuals Online Medical Library describes this increasing pressure as compartment syndrome that will slow or stop cellular perfusion with oxygen and nutrients. At this time the muscle cells begin to die, resulting in pain out of proportion to the severity of the injury. Compartment syndrome can develop in the front or rear compartments of the leg resulting in calf or thigh pain.
Muscle Pain
Pain in the calf or thigh can originate from hamstring tears, calf strains or muscle spasms. A common spasm called a charley horse, occurs when the calf muscle contracts but does not relax. The resulting pain can be severe if not relieved quickly. The U.S. National Library of Medicine reports the most common causes of a charley horse to be dehydration, medications and muscle fatigue. In each case the causative factor is a reduction in fluids and electrolytes that are essential for the control of muscle contraction.
Sciatica
This is the medical term to describe pain that radiates along the sciatic nerve, from the back down to the lower leg. Mayo Clinic physicians describe this as a symptom involving the nerves in the lower back. Depending upon the severity and the causative factor it may disappear on its own after several weeks or months.
