The risk of having a stroke can be increased by almost a third through contracting shingles, according to research.
If the infection, which is caused by the chickenpox virus, involves the eyes then the risk of having a stroke is 31% higher.
Scientists in Taiwan studied 7,760 adults between 1997 and 2001 who had been treated for shingles and also 23,000 people who had not previously suffered from the shingles infection - known as "control" individuals.
The research found that the risk of having a stroke after contracting shingles was four times higher if the infection involved the eye or the skin around it.
Around 136 shingles patients and 306 control patients suffered from stroke in the space of a year.
The study also found that shingles led to an almost three-fold increase in the risk of haemorrhagic ("bleeding") strokes.
Shingles raised the risk of more common ischaemic strokes, caused by a blocked arteries, by 31%.
The findings were published in the American Heart Association journal Stroke.
Study leader Dr Jiunn-Horng Kang, from Taipei Medical University Hospital in Taiwan, said: "While the mechanism by which shingles increases stroke risk remains unclear, the possibility of developing a stroke after a shingles attack should not be overlooked.
"Doctors and patients must pay extra attention to controlling other risk factors for stroke, such as high blood pressure, smoking and diabetes."