As temperatures continue to soar across several parts of India, people are stepping out armed with sunscreens, umbrellas, water bottles, and every possible trick to survive the sweltering summer heat. But beyond dehydration, tanning, and exhaustion, experts say the rising temperatures may also be quietly affecting something far more serious - your blood pressure.
Weather has long been linked to various health conditions, and growing research suggests that extreme heat and humidity can influence blood pressure levels in ways many people may not realise. While some individuals may experience a drop in blood pressure due to dehydration and widening of blood vessels in hot weather, others, especially those with existing heart conditions or hypertension, may face fluctuations that put added strain on the cardiovascular system.
A 2024 study involving nearly 6,000 children from the Chongqing Health Cohort explored how temperature and humidity affect blood pressure levels over time. Researchers observed that higher air temperatures were linked to decreased blood pressure levels, while extreme humidity levels showed a U-shaped relationship with BP. The study further highlighted that “greater variability in air temperature was linked to increased BP levels,” and lower average temperatures were associated with a higher risk of elevated blood pressure. Researchers also pointed out that lipid profiles such as LDL and total cholesterol may partly mediate this relationship.
We spoke to Dr Aravinda S. N. to understand how rising temperatures and extreme weather conditions can affect blood pressure, who is most at risk, and what precautions people should take during intense summer heat.
How does hot weather affect blood pressure?
According to Dr Aravinda S N, extreme summer temperatures can significantly affect the heart and blood vessels, often leading to unpredictable changes in blood pressure. “People usually associate summers with dehydration and fatigue, but heat can also quietly impact cardiovascular health,” he explained.
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Dr Aravinda noted that the body naturally tries to maintain its core temperature during extreme heat by widening blood vessels, a process known as vasodilation. While this helps release heat through the skin, it can also lower blood pressure.
“In elderly individuals and those already taking medication for hypertension, this drop can become more pronounced,” he said.
He added that excessive sweating and fluid loss during hot weather reduce blood volume, increasing the chances of low blood pressure, dizziness, and weakness. At the same time, dehydration forces the heart to work harder to circulate blood.
“When the body loses water and essential salts, the cardiovascular system comes under stress. This may sometimes trigger fluctuations or even sudden increases in blood pressure,” he explained.
What symptoms should people watch out for?
Dr Aravinda said heat-related blood pressure changes can present through a range of symptoms, depending on whether BP drops or rises.
People experiencing low blood pressure may develop dizziness, weakness, fainting, blurred vision, nausea, or unusual tiredness. “Some individuals feel light-headed after standing up suddenly or after spending prolonged periods outdoors,” he said.
On the other hand, heat stress linked to elevated blood pressure may trigger headaches, chest pain, palpitations, breathing difficulty, and severe exhaustion.
He stressed that regular BP monitoring becomes especially important during peak summer months because symptoms may not always appear immediately.
“Confusion, chest pain, severe dizziness, breathing difficulty, or loss of consciousness should never be ignored, as these can indicate serious heat-related complications requiring urgent medical attention,” Dr Aravinda cautioned.
Does humidity make the problem worse?
Apart from temperature, humidity also plays a major role in how the body responds to heat, Dr Aravinda pointed out.
Normally, the body cools itself through sweat evaporation. However, during humid conditions, sweat does not evaporate efficiently, making it harder for the body to cool down.
“This creates additional heat stress and puts extra strain on the heart and blood vessels,” he said.
He also warned that hot and humid nights can be particularly risky because the body does not get enough time to recover from daytime heat exposure.
“Disturbed sleep and prolonged heat exposure can negatively affect heart health and blood pressure regulation,” he added.
Who is most at risk, and how can people protect themselves?
According to Dr Aravinda, elderly individuals, pregnant women, children, outdoor workers, and people with hypertension, diabetes, kidney disease, or heart conditions are more vulnerable to summer-related BP fluctuations.
He also noted that people taking blood pressure medications or diuretics face a higher risk of dehydration during extreme heat.
“Patients should never stop their medications without medical advice. Instead, they should focus on adequate hydration and regular blood pressure monitoring,” he said.
He stressed that staying hydrated remains one of the most effective ways to prevent heat-related blood pressure problems.
“The body needs enough fluids to maintain circulation and regulate temperature properly,” he explained.
Along with water, he recommended fluids such as coconut water, buttermilk, homemade electrolyte drinks, and water-rich fruits. He advised limiting alcohol, excessive caffeine, sugary beverages, and highly processed salty foods, as these can worsen dehydration and make BP control more difficult.
“The safest time for outdoor activities or exercise is during early mornings or evenings when temperatures are relatively lower,” he added.
He also recommended wearing light cotton clothing, ensuring proper indoor ventilation, avoiding direct sunlight for long periods, and checking blood pressure regularly during summer months to detect fluctuations early and prevent complications.
This story is done in collaboration with First Check, which is the health journalism vertical of DataLEADS