Does blood pressure variability affect the summer associated symptoms amongst females?

Blood pressure usually increases in winter and decreases in summer i.e, shows seasonal variation. In a tropical country like India women often complain off prominent symptoms like dizziness, giddiness, fainting and weakness during summer months. The objective was to study the prevalence of above symptoms which are common during summer and its association with variation in blood pressure among normotensive healthy females aged 18-40 years.

The present study was carried out on 132 women as a prospective observational study which included 2 home visits to the participants in the two different seasons in the months of May-June (summer) and December-January (winter) based on the data provided by the meteorological department of Government of India. Blood pressure and pulse rate (hemodynamic variables) was measured in these seasons and information was collected on the occurrence of the symptoms in these seasons.

There was mean decrease of 11.07 +/- 10.29 mm of Hg in Systolic blood pressure & 6.79 +/-6.88 mm of Hg in diastolic blood pressure in summer as compared to winter. The symptoms in the form of weakness, dizziness and blackout which are generally perceived by women in this area to be due to low blood pressure were observed in 32.6% of the study subjects in summer compared with 2.3% in winter. The difference was statistically highly significant (p < 0.001). There was no significant difference between the mean value of electrolytes, creatinine and urea in the cases and the controls.

Thus the seasonal variation in blood pressure rather than electrolytes abnormality may be responsible for these symptoms.