section_path: Epidemiology
section_name: Epidemiology
paragraph_text: Epidemiology
  
  Stroke was the second most frequent cause of death worldwide in 2011, accounting for 6.2 million deaths (~11% of the total). Approximately 17 million people had stroke in 2010 and 33 million people have previously had stroke and were still alive. Between 1990 and 2010 the incidence of stroke decreased by approximately 10% in the developed world and increased by 10% in the developing world. Overall, two-thirds of stroke occurred in those over 65 years old. South Asians are at particularly high risk of stroke, accounting for 40% of global stroke deaths. Incidence of ischemic stroke is ten times more frequent than haemorrhagic stroke.
  
  It is ranked after heart disease and before cancer. In the United States stroke is a leading cause of disability, and recently declined from the third leading to the fourth leading cause of death. Geographic disparities in stroke incidence have been observed, including the existence of a " stroke belt " in the southeastern United States, but causes of these disparities have not been explained.
  
  The risk of stroke increases exponentially from 30 years of age, and the cause varies by age. Advanced age is one of the most significant stroke risk factors. 95% of stroke occurs in people age 45 and older, and two-thirds of stroke occurs in those over the age of 65.
  
  A person's risk of dying if he or she does have stroke also increases with age. However, stroke can occur at any age, including in childhood.
  
  Family members may have a genetic tendency for stroke or share a lifestyle that contributes to stroke. Higher levels of Von Willebrand factor are more common amongst people who have had ischemic stroke for the first time. The results of this study found that the only significant genetic factor was the person's blood type. Having stroke in the past greatly increases one's risk of future stroke.
  
  Men are 25% more likely to develop stroke than women, yet 60% of deaths from stroke occur in women. Since women live longer, they are older on average when they have stroke and thus more often killed. Some risk factors for stroke apply only to women. Primary among these are pregnancy, childbirth, menopause, and the treatment thereof (HRT).