Is drinking more water always better? Nephrologist Dr Suman Sethi explains the truth about hydration and kidney health

There is a difference between staying well-hydrated and drinking excess water. Dr Suman Sethi explains where to draw the line and why it is important.

Water is often considered the simplest prescription for good health, and rightly so. It helps the kidneys remove waste products, maintain electrolyte balance, and regulate blood pressure.

However, in an interaction with HT Lifestyle, Dr Suman Sethi shared that it is a myth that drinking excessive amounts of water automatically makes the kidneys healthier. The truth is, more is not always better.

“Our kidneys are remarkably efficient organs,” noted the nephrologist. “For most healthy individuals, the body's natural thirst mechanism is enough to signal when you need fluids.”

Daily water requirements vary from person to person depending on factors such as age, climate, physical activity, diet, and underlying health conditions. As per Dr Sethi, there is no one-size-fits-all number that everyone should aim for.

Effects of drinking excessive water

The importance of adequate hydration cannot be overstated, especially during hot weather, exercise, fever, or illnesses that cause fluid loss.

Drinking excessive water does not improve kidney function.

However, drinking water far beyond the body's needs does not “flush” the kidneys or improve their function.

“In fact, consuming excessive amounts of water in a short period can dilute sodium levels in the blood, leading to a serious condition called hyponatremia, which may cause headaches, nausea, confusion, and in severe cases, seizures,” noted the nephrologist.

On the other hand, she cautioned that individuals with chronic kidney disease, heart failure, or those undergoing dialysis often need personalised advice regarding fluid intake.

“For them, drinking too much water can lead to swelling, breathlessness, elevated blood pressure, and additional strain on the heart and kidneys. This is why following social media trends or blanket hydration advice can sometimes do more harm than good,” stated Dr Sethi.

How to keep hydration level in check?

As per Dr Sethi, a practical way to judge hydration is to pay attention to the body.

“Feeling thirsty, having dark yellow urine, or experiencing dizziness can indicate dehydration, while pale yellow urine generally reflects adequate hydration. However, urine colour alone isn't always a perfect guide, as certain foods, vitamins, and medications can influence it,” she shared.

The key message is simple: hydration should be smart, not excessive. In the words of the nephrologist, “Listen to your body's signals, stay hydrated according to your lifestyle and environment, and seek medical advice if you have kidney disease or other chronic conditions.”

Healthy kidneys don't need extreme water intake; they need consistent care, a balanced diet, regular health check-ups, and good control of conditions like diabetes and hypertension. When it comes to water, the right amount is always better than the maximum amount.

Note to readers: This article is for informational purposes only and not a substitute for professional medical advice. Always seek the advice of your doctor with any questions about a medical condition.

Dr Suman Sethi, MBBS. MD, DM, is the director and head of the Institute of Nephrology at RG Hospitals, Ludhiana. She has more than 14 years of clinical and teaching experience.