From controlling body temperature and flushing out toxins, adequate hydration plays a vital role in our general health and well-being, water is a life essential. However, while dehydration garners significant attention, overhydration, or drinking excessive amounts of water, is a condition that can have serious and sometimes fatal consequences.

Although it may sound bizarre since drinking water is said to be the solution for most health related problems it is important to recognize how much water is considered "too much" or the risks involved with being overhydrated can maintain a healthy balance.

What Is Water Intoxication?

Water intoxication, also termed hyperhydration, water poisoning or water toxemia, develops when an individual drinks much more water than the kidney can excrete. The main function of the kidneys in the human body is the processing and excretion of excess water. However, the human kidneys can process only up to 0.8 to 1.0 liters of water at a time. Drinking an amount that exceeds this may overwhelm the kidneys and put the electrolyte balance out of sync in the human body.

Electrolytes, especially sodium, are essential in maintaining fluid balance within and outside cells. Hyponatremia is the condition when sodium levels fall below 135 mmol/L, resulting from excessive water intake. This causes water to shift into cells, swelling them. In the brain, this can cause severe complications, including coma or even death.

Symptoms of Water Intoxication

The symptoms of water intoxication vary from mild to severe. Early symptoms are often similar to dehydration, which makes self-diagnosis challenging. Common symptoms include:

• Headaches
• Nausea and vomiting
• Muscle cramps or weakness
• Fatigue or drowsiness
• Confusion and disorientation

In more serious cases, water intoxication can cause seizures, loss of consciousness, or swelling in the brain. These complications can be fatal if left untreated.

A notable case occurred in 2007 when a woman participating in a water-drinking contest tragically died after consuming nearly two gallons of water in under two hours. More recently, actress Brooke Shields experienced a grand mal seizure attributed to excessive water consumption.

Causes of Water Intoxication

Water intoxication is rare, but certain scenarios can increase the risk:

1. Sporting Events and Endurance Training

These endurance athletes are prone to water intoxication, especially if they drink large amounts of water without replacing lost electrolytes. Hyponatremia usually happens during long races or marathons as individuals mistake fatigue and muscle cramps for dehydration and continue drinking water in excess.

2. Military Training

Overhydration among military personnel is usually due to severe physical activity in extreme environmental conditions. The total number of hyponatremia cases documented from 2007 through 2022 for the active duty in the United States exceeds 1,600, with a note to this problem on exertion-related overhydration.

3. Mental Health Conditions

Compulsive water drinking, known as psychogenic polydipsia, is linked with some mental illnesses such as schizophrenia and psychosis. People with these conditions tend to drink too much water, causing a hazardous electrolyte imbalance.

4. Drug Abuse

Drugs such as MDMA (ecstasy) raise the body temperature and make people thirsty, and at times, some people tend to drink excess water at events like music festivals. MDMA also leads to urine retention, thus exacerbating the dangers of water intoxication.

How Much Water Is Too Much?

The exact amount of water that causes intoxication varies from one person to another. However, drinking more than 1 liter of water per hour for several hours raises the risk. For healthy individuals, the risk of overhydration is low unless taking part in extreme physical activity or ignoring thirst cues.

Certain medical conditions, such as kidney or liver disorders, can impair the body's ability to process fluids, and even moderate water intake may be harmful. Similarly, certain medications, such as diuretics and antipsychotics, can affect the perception of thirst or fluid regulation.

How Much Water Is Enough?

The widely touted recommendation of eight 8-ounce glasses of water per day has little basis in fact. According to the National Academy of Medicine, a daily total fluid intake is about 15 cups (3.7 liters) for males and 11 cups (2.7 liters) for females, from beverage sources and from food. Usually, about 20 percent of daily hydration comes from foods such as fruits and vegetables.

A better rule of thumb is to listen to your body and drink water based on thirst. Use the color of your urine as an indicator:

• Light yellow urine indicates proper hydration.
• Dark yellow urine may indicate dehydration.

Older adults, whose thirst mechanisms may decline with age, should be proactive about maintaining hydration, especially during illness or hot weather.

Water Intoxication vs. Dehydration

The symptoms of water intoxication—such as headaches, fatigue, and muscle weakness—are similar to those of dehydration. If you are unsure which condition you are experiencing, seek medical attention immediately rather than self-treating with more water.

Preventing Water Intoxication

To avoid the dangers of overhydration:

• Drink water gradually throughout the day rather than consuming large amounts at once.
• Replace lost electrolytes post high-intensity exercise or heavy sweating.
• Consider using sports drinks or salty snacks to help replenish sodium.
• Keep track of fluid consumption during long-duration activities, and do not consume more water than the body is losing in terms of electrolytes.
• If on medications or have specific medical conditions, check with your doctor regarding the safety of drinking water.

For signs of severe water intoxication-including confusion, drowsiness, seizures, and loss of consciousness-customer is advised to seek medical assistance immediately. In the meanwhile, a salty snack would help to temporarily correct low sodium levels.

Hydration is important to health, but overhydration can be a serious risk; the secret is in finding a balance. Drink enough water to satisfy your body, but not so much that it overwhelms your system. Remember, water is life, but moderation keeps it that way.

Hyponatremia (low sodium level in the blood). National Kidney Foundation. 2023.

Water Toxicity. NIH. 2023

Exercise-Associated Hyponatremia: 2017 Update. Front Med (Lausanne). 2017

Update: Exertional Hyponatremia Among Active Component Members of the U.S. Armed Forces, 2007–2022

About 10.6 percent –15 percent of India's population suffers from some form of mental health conditions, with 15 percent of the adult population also requiring active intervention.

To enable researchers to gather as well as systematically document data on patients with major forms of mental illness, neuroscientists in India have developed CALM-Brain — a digital repository of data on brain structure and function from a range of psychiatric disorders.

CALM-Brain contains data from over 2,000 participants from 900 families across the country.

CALM-Brain will help clinicians and researchers

• to understand the onset of neuropsychiatric disease
• check progression
• decode underlying biological changes
• provide better diagnosis
• plan personalized treatments for patients.

“CALM-Brain was conceived as a method to assemble data from multiple scales of analysis of brain structure and function on a single platform. We believe that the application of modern methods of data analysis to this dataset will help bridge the gap between these scales of analysis,” said Prof. Raghu Padinjat, CBM co-ordinator at CBM-NCBS, in a statement.

Also read: World Happiness Report 2026 Flags Social Media Harms On Adolescents' Mental Well-being

What Is CALM-Brain?

CALM-Brain is the result of collaborative efforts of researchers at the Rohini Nilekani Centre for Brain and Mind (CBM) — a partnership between the National Institute of Mental Health and Neuro Sciences (NIMHANS) and the National Centre for Biological Sciences (NCBS) - TIFR.

CALM-Brain is India’s first-of-its-kind repository of clinical, neuroimaging, behavioral, genetic, and other datasets on disorders such as:

• addiction,
• bipolar disorder,
• dementia,
• obsessive compulsive disorder (OCD)
• schizophrenia.

• Functional Magnetic Resonance Imaging (fMRI)
• Near Infrared Spectroscopy (NIRS)
• electroencephalogram (EEG)
• observations of cognition
• eye-tracking
• genetic analyses of blood samples
• clinical assessments.

The dataset is also linked to a biorepository of stem cells, which can be used to perform biological research in psychiatry to understand the origins of such severe mental illnesses.

“The primary goals of the project are to identify biological markers of severe psychiatric illnesses, which cut across traditional diagnostic frameworks. In addition, we will try to identify fundamental biological mechanisms of the disease and medication response,” said Prof. Y.C. Janardhan Reddy, CBM coordinator at CBM-NIMHANS.

Burden Of Mental Illnesses In India

Mental wellness is a major health and economic concern in India. The World Health Organization (WHO) estimates India’s economic loss due to mental health conditions to be USD 1.03 trillion (2012-2030).

Recently, health experts and policymakers, as part of the government-led Post-Budget Webinar series, highlighted the growing burden of mental and neurological disorders in India and also stressed the urgent need to strengthen institutional capacity to meet emerging healthcare demands.

"One in seven Indians is affected by mental health disorders, while several states continue to face a treatment gap ranging from 70 to 90 percent," the experts said.

They added that "neurological and mental health conditions are among the leading contributors to disability-adjusted life years (DALYs)" among citizens.

To address the rising burden, the government aims to launch NIMHANS-2 — first announced by Finance Minister Nirmala Sitharaman during the Union Budget 2026-27 — to deliver specialized care for mental health and neurological disorders in north India.

"In addition, the Central Institute of Psychiatry, Ranchi, and the Lokopriya Gopinath Bordoloi Regional Institute of Mental Health, Tezpur, will be upgraded as regional apex institutions to strengthen mental healthcare services in the eastern and north-eastern regions," FM Sitharaman said.

Metformin has remained the safe and most effective first-line treatment for Type 2 diabetes for the last 60 years. The anti-diabetic drug has been known to work through the liver and gut to lower blood sugar levels and improve the way the body handles insulin.

However, a new study has, for the first time, shown that metformin probably works through the brain, and neurons in a specific region boost its anti-diabetic effects.

The findings open up potential for more targeted and effective diabetes therapies as well as for improving brain health.

The international team of researchers led by those at Baylor College of Medicine, in the US, decoded a brain-based pathway involved in metformin's ability to lower blood sugar.

They found that the widely used diabetes medication switches off a key protein and activates specific neurons, and lowers blood sugar through a previously hidden pathway.

"Metformin is not just working in the liver or the gut, it's also acting in the brain. We found that while the liver and intestines need high concentrations of the drug to respond, the brain reacts to much lower levels," said corresponding author Dr. Makoto Fukuda, associate professor of pediatrics - nutrition at Baylor.

Metformin: New Brain Pathway

The new study, published in Science Advances, targeted a small protein called Rap1 -- located in a brain region known as the ventromedial hypothalamus (VMH).

Mice studies proved that metformin fights blood sugar by suppressing the activity of Rap1 in VMH.

To prove the findings, the team deployed genetically engineered mice without Rap1 in the brain.

In mice with a high-fat diet that models type 2 diabetes, low doses of metformin did not improve their blood sugar levels.

On the contrary, when metformin was delivered in very small amounts directly into the brains of diabetic mice, it effectively lowered blood sugar levels.

Further, the team found that SF1 neurons located in the VMH are helping metformin to fight diabetes.

When the team measured the electrical activity of these neurons, they found that metformin’s activity increased only when Rap1 was present

The findings demonstrated that Rap1 is required for metformin to activate these brain cells and regulate blood sugar.

"This discovery changes how we think about metformin," Dr. Fukuda said.

Also read: Indian Drug Regulator Flagged 90 Combination Medicines Sold Without Approval

Metformin: Other benefits

Metformin has also shown potential to boost fertility levels in people with polycystic ovary syndrome (PCOS) -- a condition that affects how the ovaries work.

Metformin treats PCOS by lowering insulin and blood sugar levels. This can also improve ovulation and encourage regular periods.

Metformin has previously shown its potential for slowing brain aging and improve lifespan.

While metformin is safe for most adults and children aged 10 years and older, the drug may not suitable for some people. this includes people who:

• have ever had an allergic reaction to metformin or other medicine
• have uncontrolled diabetes
• have liver or kidney problems
• have a severe infection
• are being treated for heart failure or have recently had a heart attack.

Indians are facing an increasing burden of heart diseases, and mortality is rising faster compared to other countries. A top US cardiologist has now shared the major risk factors that range from genetics to obesity to pollution.

Cardiovascular diseases (CVDs) cause nearly 31 per cent of all deaths in India, according to the latest Sample Registration Survey (SRS) 2021-2023 data from the Registrar General of India, released in September 2025.

The SRS report highlighted cardiovascular diseases as the leading cause of death, especially among adults over 30.

Speaking exclusively to HealthandMe, Dr. Sripal Bangalore, Professor of Medicine at New York University School of Medicine, highlighted the key reasons why India is seeing a huge burden of heart diseases.

"I think it’s a combination of traditional and non-traditional risk factors. Globally, we are seeing the burden of obesity increasing, and specifically in India, genetic factors and non-traditional risk factors also play a role," Dr. Sripal said.

"There is a growing investigation into lipoprotein(a) and other causes of cardiovascular disease (in India). Obesity is a major risk factor, and I’m sure stress and pollution also add to it, with more and more data supporting these links," he added.

Data from the World Heart Federation showed that heart disease kills 28.6 lakh Indians every year. In the recent past, India has also been seeing a significantly higher rate of heart attacks and related deaths, even in children as young as 12 years old.

Also read: AHA’s New Dyslipidemia Guidelines Stress Early Screening, Lifestyle Management

What Factors Are Driving This Trend

"I think we need to know that part of it tends to be non-traditional, because in the Western world most of it is explainable by traditional risk factors like hypertension, diabetes, and hypercholesterolemia," Dr. Sripal said.

"What we see in India is that it is less about those risk factors, but more about non-traditional ones, including potentially genetic factors and lipoprotein(a)," the doctor added.

The Indian-origin interventional cardiologist also cited lifestyle factors such as stress and pollution that are significantly adding to the increased risk of cardiovascular events in the country.

AHA 2026 Cholesterol Guidelines: Relevance For India

Recently, the American Heart Association (AHA) released cholesterol guidelines, which stressed the importance of early screening, starting with teenagers.

The guidelines call for early intervention through early screening and healthy lifestyle changes, starting from childhood.

It recommends:

• Children (9-11 years): Cholesterol screening if never done before.
• Adults (30-79 years): Evaluate 10- and 30-year ASCVD risk to determine the need for early intervention

"India is a good example where LDL levels (bad cholesterol) may not be very high, like in the Western world. Many times, HDL cholesterol (good cholesterol) tends to be lower, and there are other risk factors, including lipoprotein(a), which seems to be elevated here," Dr. Sripal said.

How To Improve Heart Health

The doctor also explained whether overall diet quality matters more than just cholesterol intake.

"Diet adds to the totality of everything that we do, including increasing the risk of obesity. Cholesterol may explain some part of it, but having a heart-healthy diet is critically important," Dr. Sripal said.

The cardiologist highlighted the need to increase the intake of fruits and vegetables, as consuming natural foods is critically important.

Importantly, he also emphasized at least making sure that you have a lipid panel to check your cholesterol levels.

"We are assuming that you are staying healthy and not smoking. Checking blood pressure, it depends on your age, but at least once a year, checking your lipid panel would be critically important," Dr. Sripal told HealthandMe.

As a cardiologist, he shared that to boost heart health, the key is

• to make sure that you lead a healthy lifestyle,
• stay away from smoking,
• increase physical activity,
• reduce stress.

"Pollution is one factor, and I think we can all do our part to make sure that we don’t contribute more to environmental pollution," he noted.