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.
Causes of leg cramps. The cause of leg cramps is sometimes unknown (idiopathic). In other cases, there may be an underlying condition or another identifiable cause. Idiopathic leg cramps. Although the cause of idiopathic leg cramps is unknown, there are a number of theories about what might cause idiopathic leg cramps.