Dehydration — a dangerous loss of body fluid — can be a significant contributing factor for suffering a stroke, said doctors on Tuesday, after Zerodha co-founder and CEO Nithin Kamath cited it as a possible reason behind his recent stroke.

In a post on X, Kamath on Monday revealed he suffered a mild stroke around six weeks ago. Besides poor sleep and exhaustion, he said dehydration could be a reason.

“Around six weeks ago, I had a mild stroke out of the blue. Dad passing away, poor sleep, exhaustion, dehydration, and overworking out – any of these could be possible reasons,” he posted. Kamath said that he is on the path to recovery.

“While dehydration isn’t the direct cause of stroke, it can be a contributing factor mainly in cerebral venous strokes rather than arterial strokes,” Guruprasad Hosurkar, Additional Director – Neurology, Fortis Hospital, Bannerghatta Road, Bengaluru, told IANS.

“Dehydration involves losing more fluids from our bodies than what is gained thereby causing an electrolyte imbalance in the body hence affecting various body functions. One of the least known effects of severe dehydration is that it possibly increases chances for stroke development,” added Houssein, Medical Director, Holy Family Hospital, Bandra.

The health experts explained that dehydration leads to thickening of blood, which slows blood flow to the organs including brain which in turn, can increase the risk of blood clot formation and cause stroke.

“During episodes of dehydration, blood thickens making it difficult for the heart to effectively pump blood through the arteries. This in turn may lead to low blood pressure as well as low supply of blood to the brain (insufficient cerebral perfusion), thus increasing risks for developing strokes,” Houssein told IANS.

“Dehydration can also make vessels in the brain narrow so much which then reduces flow of blood together with oxygen needed by vital tissues in brain areas. Additionally, inadequate hydration affects temperature regulation which might result in heat related illnesses stressing out the cardiac system further,” he noted.

A large study published in the Lancet journal eBioMedicine, last year, showed that people who aren’t hydrated enough may age faster and even have a higher risk for chronic diseases that could result in early death. Not consuming enough water can increase the risk of death by 20 per cent, it showed.

Staying hydrated is crucial for overall health, including reducing stroke risk, said the experts. “Drink plenty of fluids throughout the day, particularly during hot weather or physical activity,” they said.

Kamath is also known for his fitness advice on social media. While he reiterated the need to keep oneself fit, the stroke, he acknowledged, left him questioning why a person who’s fit and takes care of himself could be affected.

“Stroke is usually associated with old age and pre-existing conditions like hypertension and diabetes; however, it is essential to note that young people who seem healthy can become stroke victims. In this age group, apart from dehydration, unappreciated cardiovascular conditions as congenital heart diseases, or abnormalities in blood supplying vessels to the brain, often go unrecognised,” Houssein explained.

Drug abuse, trauma or brain injury, autoimmune disorders, and infectious diseases are other reasons that result in strokes among young and fit persons.

The doctors stressed the need for regular medical check-ups and screenings particularly among those whose family history has incidences of strokes or heart diseases; eating a balanced diet, exercising regularly, maintaining a healthy weight, and avoiding smoking and excessive alcohol consumption.