Why dehydration in winter is a hidden risk for brain health, neurologist explains

When people think of dehydration, they usually imagine hot summer days. Few realise that winter can also cause dehydration, and it can quietly affect brain health. Winter dehydration is often overlooked because cold weather reduces the feeling of thirst. Yet, the body continues to lose fluids through the skin, lungs, and even urine. If these fluids are not replaced, the brain can be one of the first organs to feel the strain.

Dr Madhukar Bhardwaj, Director and Head of Neurology at Aakash Healthcare, warns that this misconception—that dehydration only happens in summer—can be dangerous. “Even mild dehydration can affect blood flow, making the blood thicker and harder to circulate,” he says. Thicker blood slows circulation and puts more pressure on the heart and blood vessels, which can affect brain health.

In winter, the air is dry, and indoor heating further increases water loss from the body. People also tend to drink less because they do not feel thirsty. This combination of factors can quietly lead to dehydration, especially in seniors and people with chronic health conditions like high blood pressure, diabetes, or heart disease. These individuals are more vulnerable because dehydration can worsen blood flow issues, increasing the risk of stroke and other cardiovascular problems.

Symptoms of winter dehydration are often subtle. Unlike summer dehydration, where thirst or weakness is noticeable, winter dehydration can present as unusual tiredness, irritability, or feeling colder than usual. Seniors are at higher risk because the natural sense of thirst diminishes with age. Many older adults only drink water when they feel extremely thirsty, and in winter, this sensation may not even occur. People taking certain medications, such as diuretics or blood pressure medicines, are also more prone to dehydration because these drugs increase fluid loss.

How to protect your brain in winter

Neurologists note that strokes and other brain-related health problems tend to rise in winter. Cold weather can narrow blood vessels, making blood flow harder. Dehydration adds another layer of risk because thicker blood increases the chance of clot formation. “Hydration is not just a summer concern,” Dr Bhardwaj says. “Older adults and people with chronic illnesses should pay special attention to their fluid intake year-round to protect brain health.”

ALSO READ: Explained: Why China’s contraceptive tax shows the limits of pro-natalist policies

ALSO READ: India’s BRICS presidency in 2026: Can New Delhi balance the US while leading the Global South?

Staying hydrated in winter does not require major changes. Simple, consistent habits can make a big difference. Drinking water at regular intervals—even if you do not feel thirsty—is key. Warm fluids like soups, broths, and herbal teas are excellent choices for winter hydration. Water-rich foods such as fruits, vegetables, stews, and dals also help maintain proper fluid balance.

Monitoring urine colour is another useful tip. Pale yellow usually indicates adequate hydration, while darker urine suggests the need for more fluids. People should also limit excessive caffeine and alcohol, as both can increase fluid loss and contribute to dehydration.

Seniors, in particular, should be encouraged to drink fluids consistently, even without thirst cues. Families can help by offering warm drinks throughout the day and including water-rich meals in daily routines. Awareness is the first step toward preventing winter dehydration, which quietly increases stroke and cardiovascular risks.

Dr Bhardwaj emphasises that simple, steady hydration protects the brain and overall health. Dehydration in winter may not feel urgent, but its effects can be serious if ignored. By drinking regularly, eating hydrating foods, and monitoring fluid intake, people can reduce the hidden risks and keep their brain functioning well throughout the colder months.

In conclusion, dehydration in winter is often unnoticed but can affect brain health significantly. Cold weather reduces thirst, indoor heating and dry air increase fluid loss, and older adults or people with chronic illnesses are especially at risk. Thicker blood caused by dehydration increases the likelihood of clot formation and stroke. Simple measures like drinking water regularly, eating water-rich foods, including warm fluids in your diet, and monitoring urine colour can prevent winter dehydration. Staying hydrated is essential for brain health, no matter the season, and consistent habits today can protect against serious risks tomorrow.