Zerodha CEO Nitin Kamath has mild stroke: How stress, dehydration and lack of sleep can up your stroke risk

How can stress directly and indirectly cause a stroke?

Stress impairs hormones, which can affect our sympathetic (that makes us alert) and parasympathetic (that calms us down) nervous systems. The sympathetic nervous system drives hormones like catecholamines which elevate BP and heart rates. If a person is under chronic stress, they can develop hypertension or tachycardia which is the medical term for a heart rate of over 100 beats a minute. Because your heart beats too often, it doesn’t have the time it needs to fill with blood between beats. Irregular blood flow can result in clotting.

Chronic stress and anxiety increase inflammation in your arteries, which over time constricts or stiffens up blood vessels, decreasing blood flow to your brain. This makes it easier for blood clots to form or for vessels to leak or burst, releasing plaques and triggering a stroke. Even a slight increase in stress and anxiety levels may raise stroke risk, according to a study by the American Heart Association. Researchers followed more than 6,000 people over 22 years and found that those with the highest stress levels were 33 per cent more likely to have a stroke than those who felt less anxious or stressed.

Basically, stress raises the direct risk factors of the stroke like hypertension, diabetes and obesity. Sleep is another important aspect. When we work without sleep, we push our sympathetic system into an overdrive. This raises cortisol levels which cause higher reactivity in blood vessels and blood pressure. Basically you are driving the machine too fast and not giving a car a break. Dehydration thickens the blood because there is lesser water volume. When the blood becomes thick, it can actually clot faster than otherwise.

Why is over exercising a problem?

While there is data which says that exercise is beneficial for your health, there is no data which says that if you exercise for three hours rather than one hour it is better for you. In fact, over exercising can increase your heart beat. It can raise your blood pressure, disturb fluid balance and can upset the normal homeostasis of the body. Whenever we try to disturb the normal ecosystem of the body, it can react in extreme ways. Not everyone is made to run 40 kilometres.

What should we do to prevent these risk factors?

You have to address many factors together. Check for family history and some other imbalances in the blood which you don’t know about. In our country, the higher level of homocysteine, an amino acid, in the blood makes it more prone to clotting. So do a comprehensive health checkup of your biomarkers. The rest is very simple. Exercise for about 30-45 minutes at least five times a week. Don’t put on more weight than what is allowed in your height category, give up sedentary behaviour, keep your blood sugar, cholesterol and blood pressure in check. Correct your diet. Avoid smoking, alcohol and caffeine. Sleep for at least seven to eight hours. If you were to do all this, you could reduce your risk of stroke by 50 per cent.

What is a mild and major stroke? Can someone who has a mild one have another episode?

Every person who’s had a stroke, major or minor, is at a very high risk of stroke. A minor stroke causes little or no damage to brain cells. It doesn’t cause major deficiency in the body and allows you to resume normalcy faster. A major stroke causes paralysis, speech loss, motor function impairment and coordination mismatch. So the patient has difficulty walking or thinking coherently.

There has to be an individual analysis of why they had a stroke and what are their risk factors. Most stroke patients require blood thinners and medicines to prevent future episodes. Minor stroke gives you a warning to mend your lifestyle and address your risk factors.