If the brain's blood supply is decreased too much, the person may pass out (syncope). Symptoms may worsen when changing position from lying down or sitting, to standing up. In addition to feeling dizzy, associated symptoms may include: 1  Sweating. 2  Weakness. 3  Nausea and vomiting. 4  Shortness of breath. 5  Chest pain.
Although most muscle cramps are harmless, some may be related to an underlying medical condition, such as: 1  Inadequate blood supply. Narrowing of the arteries that deliver blood to your legs (arteriosclerosis of the extremities) can produce cramp-like pain in your legs and feet while you're exercising. 2  Nerve compression.
When the cause is found, cramping can be due to prolonged sitting or leg position during sedentary activity. Perhaps most commonly, cramps can be due to overuse of muscles that are not accustomed to exercise. The second most common cause is dehydration. Cramps can also be caused by electrolyte and metabolic disorders. Diuretic drugs can commonly cause cramping through dehydration, sodium or potassium depletion.