Definition of Vascular spasm:

A vascular spasm is a sudden, brief tightening of the muscle cells inside the walls of a blood vessel.

Causes, incidence, and risk factors:

The brief tightening of muscle cells inside the walls of a blood vessel cause the blood vessel to close or narrow significantly. This stops blood flow.

Vascular spasms (and heart attacks) may be caused by the use of cocaine, as a result of tobacco, or by irritation of the vessel from the inside (for example, by a catheter) or outside (from a nearby injury or tear).