These weather-related variations in blood pressure is more in age groups above 65 years. Lowering systolic BP by 10-12mmHg, diastolic BP by 5-6mmHg causes relative risk reductions of 35-40% in stroke,12-16% for coronary heart disease within 5 years of initiation of treatment,” explains Dr. T. Radhakrishna, Senior Consultant, Internal Medicine, Fortis Hospital, Richmond Road, Bangalore.