Stroke caused by subarachnoid hemorrhage occurs more commonly among smokers than those who do not smoke. The risk, however, appears to be higher in female smokers.

Subarachnoid hemorrhage, or SAH, is characterized by bleeding inside the lining of the brain. Findings of a new research, which was published in the American Heart Association's journal Stroke, have found evidence that SAH is up to eight times more common among female smokers who smoke more than a pack of tobacco per day compared with nonsmokers.

Although male smokers are also at risk, the research has revealed that the likelihood of men who smoke the same amount of cigarettes to suffer from this serious type of stroke is only threefold. Even light smoking can triple women's likelihood to suffer from SAH, the researchers have found.

SAH is attributed to about 3 percent of all strokes and often affects younger people. This type of stroke is commonly caused by a ruptured brain aneurysm — a bulging and weak spot in the wall of an artery supplying blood to the brain that can burst anytime, as well as head injury. Of those who suffer from SAH, about one in five dies.

"Smoking has a dose-dependent and cumulative association with SAH risk, and this risk is highest in female heavy smokers. Vulnerability to smoking seems to explain in part the increased SAH risk in women," the researchers wrote in their study, which was published on July 21.

For the research, Joni Valdemar Lindbohm, from the University of Helsinki in Finland, and colleagues looked at the data of 65, 521 adults who were followed for 21 years on average.

The researchers found that among light smokers who smoked between one to 10 cigarettes per day, women have three times the risk for SAH and men have twice the risk compared with those who do not smoke.

Among the subjects who smoked between 11 and 20 cigarettes daily, women have fourfold risk and men have double the risk of suffering from SAH.

The research, however, also showed the benefits of quitting smoking. Researchers found that the subjects who quit the habit significantly reduced their likelihood of suffering from subarachnoid hemorrhage. After six months of quitting smoking, the risk of smokers were found to be of the same level as those of nonsmokers.

"Our results suggest that age, sex and lifestyle risk factors play a critical role in predicting which patients are at risk for subarachnoid hemorrhage and emphasize the importance of effective smoking cessation strategies," Lindbohm and colleagues said.