It may be caused by emotional stress, pain, pooling of blood in the legs due to sudden changes in body position, heavy sweating or the sight of blood. It also may result from several heart, neurologic, psychiatric, metabolic and lung disorders. It may be a side effect of some medicines. It s a benign and most frequent cause of fainting. However, life-threatening conditions may also manifest as syncope.
NMS is more common in children and young adults, although it can occur at any age.
NMS happens because blood pressure drops, reducing circulation to the brain and causing loss of consciousness. If the syncope is prolonged, it can trigger a seizure. Placing the person in a reclining position will restore blood flow and consciousness and end the seizure. So, extensive medical work-up is rarely needed. A careful physical examination by a physician, including blood pressure and heart rate measured lying and standing, is generally the only evaluation required.