Cramps in the legs and feet can cause moderately painful reactions that may last a few minutes or longer. Muscle cramps occur when a muscle involuntarily contracts and cannot relax. Cramping may include a part of a muscle, the entire muscle or muscle groups. Doctors do not know the exact cause of cramps, according to the American Academy of Orthopaedic Surgeons. However, certain situations or conditions can increase the chance of getting leg and foot cramps.
Endurance athletes, including marathon runners, or older people not used to strenuous physical activity can suffer from cramps. For athletes, leg, calf or thigh cramps may occur following intense exercise. Inadequate stretching before or after exercise may cause cramping. Inadequate blood supply can narrow the arteries and produce cramps in the legs and feet while exercising, according to MayoClinic.com. The cramps may go away after exercising. However, poor blood circulation could indicate arteriosclerosis, which can increase the risk of heart disease.
According to the American Academy of Orthopaedic Surgeons, beginning in their 40s, many people lose muscle, often because they do not exercise as much as they once did. The muscles do not work as quickly or as effectively, especially when confronted with sudden physical activity. The muscles do not respond to sudden changes in exercise or temperature, which can lead to leg and foot cramps.
Excess heat can cause foot and leg cramps. Young children and people over age 65 have an increased risk of developing cramps. Being overweight or taking certain medications may contribute to muscle cramps. Dehydration and depletion of salt and minerals can occur when working or exercising in the heat, according to the American Academy of Orthopaedic Surgeons. Loss of fluids tends to cause muscle spasms. Cramping may get worse for people who have too little potassium, calcium or magnesium in their diets. Some diuretics for high blood pressure cause a loss of potassium.
Compression of nerves in the spine can cause cramping and pain in the leg, MayoClinic.com states. Conditions such as hormonal imbalances; diabetes; low blood sugar; anemia; and disorders of the kidney, thyroid and nerves can lead to muscle cramping.
Night leg cramps often involve the calf muscles and also the feet or thighs. Night cramps increase with age or for women who are pregnant, explains MayoClinic.com. The cramps are usually harmless, but in rare cases can indicate underlying disorders that include peripheral artery disease or diabetes.