Do you really need 8 glasses of water daily? Nephrologist debunks 8 hydration myths

Weight, climate, diet and physical activity all influence how much water a person actually needs. (Picture Credit: Pexels)

• Drinking excess water can harm kidney health and dilute vital electrolytes
• Hydration needs differ by weight, climate, diet, and activity; no one-size-fits-all rule.
• Overhydration risks include hyponatremia, kidney stress, and serious symptoms.

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Hydration trackers and constant reminders to drink more water have turned hydration into a lifestyle. For many millennials, drinking more water feels like a wellness routine. However, doctors are now saying that more water is not always good, especially for kidney health.

The biggest myth is the belief that everyone must drink eight glasses of water a day, says Dr Sridhar, Consultant Nephrology, Manipal Hospitals, Vijayawada. “Known as the 8x8 rule, this advice ignores how different our bodies really are.” Weight, climate, diet and physical activity all influence how much water a person actually needs. “Some people may need far less, while others may genuinely need more,” he explains.

The idea that constant hydration equals good health has also led to a dangerous assumption that drinking more water is always harmless. “Water is essential, but excess intake can dilute electrolytes like sodium, which are critical for nerve and muscle function,” Dr Sridhar warns. When the balance tips too far, the body pays the price.

Dr Sridhar shares hydration myths millennials should rethink

Myth: More water is always healthy

Overhydration forces the kidneys to work overtime. According to Dr Sridhar, “The kidneys are designed to maintain fluid balance. When you flood the system, they struggle to filter and remove the excess fast enough.” Over time, this constant pressure can disrupt mineral balance and stress kidney function.

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Myth: Clear urine means peak hydration

Urine colour is one of the simplest indicators of hydration. Pale yellow usually signals a healthy balance. “Completely clear urine can actually be a sign of overhydration,” says Dr Sridhar. Thirst, often ignored, remains one of the body’s most reliable cues.

Myth: Hydration needs are the same for everyone

Your water requirement changes with temperature, exercise, illness and diet. High-protein or salty foods demand more fluids, while sedentary days may not. “There is no universal number,” Dr Sridhar emphasises. “Hydration must be personalised.”

Myth: Over drinking has no real risks

One serious consequence is hyponatremia, a condition caused by low sodium levels in the blood. Symptoms can range from headaches and nausea to confusion, seizures and even coma. “It’s rare, but we do see cases linked directly to excessive water intake,” he tells.

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The solution to respect balance and not fear water. “Drink steadily through the day instead of gulping litres at once. Include water-rich fruits and vegetables, and adjust intake to your lifestyle and environment. Listen to your body,” Dr Sridhar advises. “Thirst exists for a reason.” For millennials raised on hydration challenges and viral wellness advice, he says that smarter hydration, not obsessive drinking, is what protects your kidneys.

FAQs on importance of drinking 8 glasses of water everyday:

Q1. Why is drinking enough water important for the body?

Water helps regulate body temperature, supports digestion, transports nutrients, flushes out toxins, and keeps organs functioning properly.

Q2. What does “8 glasses a day” actually mean?

It generally refers to about 1.5–2 litres of water daily. Individual needs may vary based on age, activity level, climate, and health conditions.

Q3. Can drinking enough water improve energy levels?

Yes. Even mild dehydration can cause fatigue, headaches, and difficulty concentrating, while proper hydration helps maintain energy and focus.

Q4. Does water help with digestion and gut health?

Water aids digestion by helping break down food and preventing constipation, supporting smoother bowel movements.

Q5. Is drinking water good for skin health?

Adequate hydration helps maintain skin elasticity and prevents dryness, though it doesn’t replace proper skincare.

Disclaimer: This article, including health and fitness advice, only provides generic information. Don’t treat it as a substitute for qualified medical opinion. Always consult a specialist for specific health diagnosis.