According to the latest research from the U.S. high blood pressure may be more difficult to control in winter.
A five-year study by a team of researchers from the U.S. Department of Veterans Affairs has found that people treated in the summer were on average 8% more likely to see their blood pressure come down to healthy levels.
The research team analysed electronic health data on 443,632 veterans who were treated for hypertension at 15 Veterans Affairs hospitals across the U.S.
For the study people with a blood pressure reading of more than 140 mm Hg systolic or more than 90 mm Hg diastolic on three separate days were identified as hypertensive.
According to lead researcher Dr. Ross Fletcher people gain weight in the winter and lose weight in the summer and people also tend to exercise more in the summer and less in the winter.
The researchers also say it was also possible that people might eat more salty foods in winter and salt has been implicated in raised blood pressure.
The researchers found the same pattern emerged from each hospital they studied, regardless of whether it was based in a warm or cold climate.
Experts say people should be aware that their blood pressure may be harder to control in the winter and be more vigilant at this time.
Experts say blood pressure is very variable even on a minute by minute basis but blood pressure levels and the rates of stroke and heart attack tended to be higher in winter.
Though part of the reason could be that cold weather constricts the blood vessels people are less likely to exercise and more likely to eat heavier meals in winter.
As a rule high blood pressure has no symptoms, which is why it is so dangerous as it can lead to major health problems including stroke, heart failure, heart attack and kidney failure.
While it is the single most important cause of premature death world-wide it can be controlled with lifestyle changes and medications.
Dr. Fletcher suggests people gain weight during winter and weight gain can contribute to hypertension and a more active summer lifestyle may be the key to dealing with the condition.
The study was presented to the American Heart Association.