Strokes are increasingly hitting younger people and the incidence of the crippling condition worldwide could double by 2030, warns the first global analysis of the problem.
Though the chances of a stroke jump dramatically with age, the growing number of younger people with worrying risk factors such as bulging waistlines, diabetes and high blood pressure means they are becoming increasingly susceptible.
Most strokes occur when a clot blocks the blood supply to the brain. Patients often experience symptoms including a droopy face, the inability to lift their arms and garbled speech. If not treated quickly, patients can be left with long-term side effects, including speech and memory problems, paralysis and the loss of some vision.
Scientists combed through more than 100 studies from 1990 to 2010 of stroke patients across the world and also used modelling techniques when there was not enough data. They found the incidence of stroke has jumped by a quarter in people aged 20 to 64 and that those patients make up almost one-third of the total number of strokes.
Researchers said most strokes still occured in the elderly and that the number of people suffering strokes was still increasing as the world's population aged.
"Some of the increase we will see in strokes is unavoidable because it has to do with people ageing, but that doesn't mean we should give up," said Majid Ezzati of Imperial College London, one of the authors of the study published online in the Lancet.
The study found the death rate from strokes dropped 37 per cent in developed countries and 20 per cent in developing countries, largely because of better diagnosis and treatment.