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.
A mineral deficiency of calcium and/or magnesium is probably the most frequent cause of night leg cramping. Cramps are often caused by a lack of potassium, resulting in an electrytic imbalance. Strenuous exercise with sweating and diarrhea or other bowel disease may cause loss of potassium and other important minerals.