Manage heatwave stress: Why those with BP, cholesterol can prevent heart attack by drinking 4-6 litres water

Why your bp levels, heart rate go up?

When the ambient temperature rises sharply around you, the body loses its capacity to adjust itself as quickly. If the air around you is cooler than your body, you radiate heat to the air easily. But during high temperatures, the heart has to pump extra hard to do so and reroutes more blood to the skin. So the heart rate as well as the blood pressure go up.

Similarly, when you are dehydrated, both the intravascular blood flow and volume go down. Then the blood thickens, stressing out the heart and hastening clot formation at times.

What does heat mean for people with bp, cholesterol and heart medication

Those with high blood pressure usually take diuretics and beta blockers to keep their levels under control. Diuretics increase urine output, so they can worsen dehydration in the body. That can result in electrolyte imbalance and hypocalcaemia or low calcium, which might interfere with the electrical impulses of the heart and trigger arrhythmia or a sudden cardiac arrest.

Beta blockers slow the heartbeat down. This means the heart cannot pump enough blood fast enough for heat exchange to happen. Some antidepressants and antihistamines can block sweating.

Scarring of heart muscle after a heart attack means your heart finds it difficult to go on an overdrive in extreme heat situations. If you have high cholesterol, then your arteries could be constricted enough and limit a blood rush to the skin.

If you are in the coastal part of the country where the relative humidity is above 75 per cent, the sweating and evaporation also put a strain on the cardiovascular system. Sweat, while lowering heat, depletes key minerals like sodium and potassium, and other minerals needed for muscle contractions, nerve transmissions and water balance. When there is too much water vapour in the air, evaporation becomes increasingly difficult and the heart works at a furious pace to enable systems to cool the body rapidly.

Hydration, hydration, hydration

However, all these risks can be eliminated by sufficient hydration. This will ensure that the body has enough blood volume to handle the extra demands triggered by heat. Even when you are not feeling thirsty, you must take four to six litres of fluids, be it as water, juices or fruit-infused water.

If you have diabetes or had a stroke, then these can dull the brain’s response to dehydration and not send thirst signals. So keep a count of litres.

However, certain health conditions like congestive heart failure and kidney disease mean patients have to consult their healthcare providers on their fluid intake.

Avoid sodas, packaged drinks and sugary beverages as they hinder water absorption from the digestive system to the bloodstream. It is for the same reason that you must stay away from caffeine and alcohol.

Be particularly wary of sudden temperature shifts. So if you are coming out of an air-conditioned environment to go outdoors, wait in a shaded area for about two to five minutes before you set out to acclimatise your body. If you are in an air-conditioned car, turn off the vents about five minutes before your destination, so that your body is ready for the transition.