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.
What Causes Leg Cramps? Leg cramps at night are called recumbency cramps, and are caused by spasmlike muscle contractions. You might also experience leg cramps after exercising if you are dehydrated. In both cases leg cramps can be caused by electrolyte or mineral imbalance in the body. If your leg cramps are brought on by exercise, you may be dehydrated.