Heatwaves may be lethal for those with hypertension

With the India Meteorological Department (IMD) reporting highs of almost fifty degrees Celsius over the weekend tensions are looming regarding heat related deaths. One key concern is the increased risk of complications in those living with hypertension.

Heatwaves have seen highs of 49 degrees in Delhi, with neighbouring Gurugram in Haryana recorded 48.1 degrees Celsius, the highest recorded temperature since 1966.

A study published last year found that between 1971 and 2019, extreme weather events in India claimed 141,308 lives. Of these fatalities, twelve percent – translating to 17,362 people dead – can be attributed to heatwave deaths.

These deaths are comprised of those that are in direct relation to the extreme weather event – for example, direct deaths by drowning during a flood, or from heatstroke during an extreme heat event. Thousands more are killed indirectly as a result of the exacerbation of underlying conditions. Hypertension is counted among these.

“Intense atmospheric temperature leads to increased blood flow to skin, causing a spike in sweating and dehydration. This leads to decrease in blood pressure especially on changing postures, that is, while getting up from a lying down or sitting position,” said Dr Ajay Agarwal, Director and HOD – Internal Medicine, Fortis Hospital, Noida, to IANS.

Data published in The Lancet found that the number of individuals living with hypertension doubled in the last three decades. The world’s hypertensive population now exceeds 1.2 billion. In India, the report found the prevalence of hypertension to be 32 percent among adult males and thirty percent among females.

These individuals are at severe risk during heat waves due to the fluctuations in blood pressure as the body attempts to stay cool. This can result in heart attacks or a stroke in affected individuals.

“Some people are at higher risk of being affected by humidity, including people over fifty, those who are overweight, or those who have heart, lung or kidney conditions. Heat and sweating also can lower the amount of fluid in the body, which can reduce blood volume and lead to dehydration. This can interfere with the body’s ability to cool off and may create strain on the heart,” Dr Ramakanta Panda, world’s leading cardiac surgeon and head of Asian Heart Institute, Mumbai, told IANS.

Health bodies across the globe recommend a number of behavioural changes during the hot weather. Staying indoors during the hottest hours of the day is recommended. Drinking plenty of water is vital to avoiding dehydration as sweating increases. Staying in the shade and using cold showers or fans to remain cool may also help. Such advice is essential whether an individual has hypertension or not, as, although the condition may increase the risk, everyone can succumb to heatstroke, and should remain cautious throughout the summer months.