Preventive measures do not fully protect an individual from having a stroke but can go far to reduce the risks of such an event. Many of the preventive measures involve lifestyle changes and are similar to those that can help prevent heart disease. Lifestyle measures include:

• Controlling high blood pressure (hypertension). Blood pressure abnormalities must be continually monitored and controlled because they are a chief contributor to strokes.
  
  
• Getting treatment for conditions that increase the risk of stroke, such as atrial fibrillation, atrial flutter, sleep apnea and diabetes.
  
  
• Learning stress management techniques and seeking help for depression or drug abuse. Cocaine, especially, has been linked to hemorrhagic stroke.
  
  
• Reducing cholesterol levels, by making lifestyle changes and taking cholesterol-reducing drugs.
  
  
• Living a healthy life, including increasing exercise level, maintaining an ideal weight and quitting smoking.
  
  
• Limiting use of alcohol to about one glass of wine or one beer per day.
  
  
• Eating a heart-healthy diet. Findings from a number of studies have illustrated how a heart-healthy diet can decrease stroke risk. For example, in one study, women who ate fish more than five times a week were found to have a significantly lower risk of stroke than women who ate fish less than once a month. Fish is rich in omega-3 fatty acids. In another study, people in rural Japan with the highest levels of vitamin C in their blood (from eating large amounts of fruits and vegetables) were found to be significantly less likely to have a stroke than those with the lowest levels. It is important to note that taking vitamin C supplements has not shown the same protective effect as eating a diet rich in vitamin C.

People may be advised by their physician to take aspirin or other antiplatelet agents to help prevent the formation of blood clots. However, aspirin should not be used as a first aid remedy for people who are having a stroke because they can make some types of stroke worse.

For patients with a blockage of 80 percent or greater, there is a significant risk of stroke even in the absence of symptoms. These patients often need more invasive treatments such as an angioplasty and stent.

A surgery known as a carotid endarterectomy is considered the standard treatment for severe blockages. This surgery is effective in preventing stroke for patients who either have significant blockage of a carotid artery or who have already experienced a stroke or transient ischemic attack (TIA). A carotid endarterectomy involves the removal of fatty build-up from the carotid arteries supplying blood to the brain. While the person is under general anesthesia, the plaque from the artery is removed along with the entire inner lining of the artery

For patients who are not good candidates for surgery, a physician may choose to further reduce the risk of stroke by recommending a procedure called carotid artery stenting. The Food and Drug Administration (FDA) approved carotid artery stents in September 2004 for use in certain patients. Like other stents, carotid artery stents are tiny mesh tubes that work by crushing arterial plaque against the wall of the artery and holding it in place. This prevents pieces from breaking off and traveling downstream, causing a stroke.

A cerebral aneurysm that has not yet ruptured may be diagnosed early, particularly if it was causing warning signs that led the patient to seek treatment. Surgery may be necessary to repair the aneurysm and prevent a hemorrhagic stroke. This surgery is sometimes called “clipping.” It involves snipping off the aneurysm before it can rupture. Another technique that is gaining attention is called the detachable coil technique. In this minimally invasive procedure, a small coil is implanted into the bulge in the arterial wall. The coil provokes an immune response from the body, which produces a blood clot inside the aneurysm that strengthens the arterial walls and reduces the risk of a rupture.