A vasospasm is an event in which a blood vessel spasms, constricting and narrowing the lumen or opening inside the vessel. There are a number of things which can cause vasospasm. Some people are predisposed to it and may experience it in response to a wide variety of stimuli, or at random. In other cases, an ongoing medical issue puts someone at risk for vasospasm. Sometimes, blood vessels spasm at random and it is not possible to determine a cause.
The primary concern with vasospasm is that when the vessel constricts, it limits the flow of blood. The tissue served by the vessel can experience ischemia, a limitation in blood supply which in turn reduces the amount of oxygen and nutrients available. If ischemia is prolonged, tissue death can occur. This can be especially problematic in the brain and heart muscle, where tissue death can lead to serious complications such as heart attacks.
Cerebral vasospasm often occurs as a result of a ruptured aneurysm. For reasons which are as yet unknown, as much as two weeks after a rupture and hemorrhage, patients can experience vasospasm. Spasms are also associated with atherosclerosis, especially around the heart, and with certain congenital conditions like Reynaud's syndrome. People of low body mass can also be at risk for vasospasm.
For someone who is prone to vasospasm, there are treatments available. Certain medications can be used to block the chemical signals which tell the blood vessels to clamp down. However, not all of these drugs can be used in the long term, and there are some potential risks and complications which vary, depending on the drug, but must be considered before starting drug therapy.
It is also possible to fit a stent so that blood flow cannot be occluded by vasospasm. This ensures that even if a vessel does start to spasm, it will remain open enough that ischemia will not occur in the tissue which the vessel is supposed to supply.
There are steps which can be taken to prevent spasms in blood vessels in some cases. For example, treating aneurysms before they rupture will reduce the risk, and also prevent damage which can occur as a result of a burst aneurysm. Preventing atherosclerosis can also help to limit the possibility of vasospasm, in addition to promoting good cardiovascular health in general. People with a family history of such problems may want to take more aggressive preventative steps for safety.