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

Sleep disturbances are among the most debilitating symptoms of Alzheimer’s disease. It often appears years before significant memory decline and other symptoms.

A new study from researchers at the University of Kentucky suggests that this sleep loss may not be permanent.

Instead, it could be driven by an immune response in the brain that may be reversible, sparking hope for new treatments.

Published in the journal Alzheimer’s & Dementia, the study found that brain immune cells called microglia, rather than amyloid plaques themselves, are the primary cause of sleep disruption in Alzheimer’s disease.

In mouse-based trials, researchers were able to restore more than two hours of sleep per day by temporarily removing these immune cells, without reducing amyloid plaques.

Can Sleep Be Restored In Alzheimer’s Patients?

For years, scientists believed that sleep problems in Alzheimer’s were caused by the accumulation of amyloid plaques or the gradual death of brain cells. However, this study points in a different direction.

Researchers discovered that when amyloid plaques begin forming in the brain, they activate microglia, the brain’s resident immune cells.

Instead of protecting the brain, these cells cause inflammation that keeps brain circuits active, preventing sleep.

Using a drug called pexidartinib (PLX3397), the researchers temporarily depleted around 87% of microglia in Alzheimer’s mouse models.

This restored over two hours of daily sleep, particularly non-rapid eye movement (NREM) sleep, which is essential for tissue repair, memory strengthening, and clearing waste products from the brain.

Notably, the improvement occurred without changing amyloid plaque levels, suggesting that inflammation is manageable.

Also read: Captain ‘Sully’ Sullenberger, ‘Miracle On The Hudson’ Pilot, Reveals Early-Stage Alzheimer’s Diagnosis

'Paradigm Shifting' Findings

Lead researcher Dr. Shannon L. Macauley, associate professor of physiology at the University of Kentucky College of Medicine, said, “Basically, we showed that it is not the plaques themselves, or solely dysfunctional neurons, that cause sleep loss but actually microglia.

Microglia are immune cells that, when they respond to plaques, kick off this elaborate cascade of inflammation, as if the microglia are partying all night, and keeping the brain awake.”

She also highlighted why losing restorative sleep can accelerate disease progression.

“That restorative sleep is super important for physical repair, learning and memory and washing out the toxins of the day. When Alzheimer’s patients lose this stage, they lose their brain’s primary cleaning cycle, creating a feed-forward loop that may drive further damage,” she explained.

First author Dr. Nicholas J. Constantino said one of the biggest surprises was that sleep problems did not worsen as amyloid plaques increased.

“I expected that as plaque burden became more severe, sleep disruption would also worsen. The disruptions in sleep… did not worsen by 18 months, despite more than double the amount of plaque burden,” Constantino said.

Also read: What Is Type 3 Diabetes? Insulin Resistance In The Brain That Could Trigger Alzheimer’s

Why Do Alzheimer’s Patients Lose Sleep?

Poor sleep and Alzheimer’s create a vicious cycle. Sleep deprivation reduces the brain’s ability to clear amyloid-beta and tau proteins, which can accelerate disease progression, while worsening sleep.

Sleep disturbances affect up to half of people living with Alzheimer’s disease. The disease disrupts sleep due to various reasons:

Overactive microglia: As shown in the new study, immune cells become chronically activated by amyloid plaques, releasing inflammatory signals that keep the brain in a heightened state of activity.

Damage to sleep-regulating brain regions: Alzheimer’s progressively affects areas like the hypothalamus and brainstem that regulate the sleep-wake cycle.

Loss of NREM sleep: Due to lack of deep sleep, the brain’s ability to clear metabolic waste, including amyloid plagues weakens.

Circadian rhythm disruption: Degeneration of the brain’s internal clock leads to broken sleep and daytime drowsiness. This fuels confusion and agitation associated with the disease.

Obesity has always been considered as one of the contributors to heart disease, diabetes, and stroke.

Now, growing research suggests that excess body fat, particularly in your 40s and 50s, may also accelerate brain aging and raise the risk of long-term cognitive decline.

Researchers say that obesity is not just linked with memory problems but also to significant changes in the brain structure.

Maintaining a healthy weight, especially during midlife, could help prevent memory problems and overall cognitive decline.

Higher BMI Linked To Faster Brain Aging

A recent study by researchers at the University of Georgia followed more than 8,200 adults aged 50 years and older for nearly 24 years.

The researchers found that individuals whose body mass index (BMI) increased over time experienced faster declines in cognitive performance than it would with normal aging. Excess body weight affected several aspects of cognition, including memory, planning, decision-making, problem-solving, emotional regulation, and concentration.

Lead author Dr. Claire Sexton (University of Georgia College of Public Health) said, "Maintaining a healthy body weight throughout adulthood may be an important strategy for preserving cognitive health later in life."

The study adds to the evidence that preventing weight gain throughout adulthood could become crucial for reducing dementia risk.

Also read: Grade-1 Fatty Liver: More Indians Are Developing It at Lower BMIs. What's Behind the Shift?

How Does Obesity Affect The Brain?

Chronic Inflammation

Obesity causes chronic low-grade inflammation, which can potentially damaging neurons essential for learning and memory.

Insulin Resistance

The brain relies on glucose for energy. Insulin resistance, common in obesity, may impair how brain cells use glucose, affecting memory and thinking.

Reduced Blood Flow

Obesity increases the risk of hypertension, atherosclerosis and vascular disease, reducing blood supply to brain tissue and potentially accelerating cognitive decline.

Visceral Fat

Experts believe visceral fat, the fat surrounding internal organs, may be more damaging than body weight alone. It produces inflammatory chemicals linked to brain changes and dementia risk.

Also read: Beyond Weight Loss: Scientists Discover How Exercise Can Help Reverse Muscle Aging

Growing Evidence

The latest findings are supported by several years of research. A large review published in Practical Neurology concluded that obesity is associated with smaller hippocampal volume, temporal lobe atrophy, mild cognitive impairment and increased Alzheimer's disease risk.

Some studies have suggested that obesity during midlife may nearly double the risk of developing Alzheimer's disease or dementia later in life.

Another review on obesity and aging reported that higher BMI is associated with poorer verbal memory, slower information processing and reduced executive function, particularly among older adults.

In January 2026, researchers also used genetic analyses to suggest that obesity and high blood pressure may directly contribute to dementia.

Can The Risk Be Reduced?

With a few lifestyle improvements, overweight and obese individuals can maintain a healthy BMI, reducing the risk of faster brain ageing and cognitive degradation. Experts recommend focusing on overall metabolic health rather than the number on the weighing scale alone.

Maintaining a healthy weight, regular exercise, controlling blood pressure, cholesterol and diabetes, following a Mediterranean diet, getting adequate sleep, remaining socially and mentally active can help maintain a healthy body weight.

Living with someone who has hepatitis can be worrying. People tend to immediately wonder whether they are at risk simply by sharing meals, hugging, or living under the same roof.

Fortunately, the answer depends on the type of hepatitis, and in most cases, everyday household contact does not spread the virus.

Dr. Shalimar, Prof. Department of Gastroenterology, AIIMS explains, "Hepatitis means inflammation of the liver. There can be many causes, but viral hepatitis is one of the most common. There are different hepatitis viruses, including A, B, C, D, and E. Some cause acute illness, while others can lead to long-term liver damage, including cirrhosis and liver cancer."

Experts say misinformation surrounding hepatitis often leads to unnecessary fear and stigma, causing patients to feel isolated. Understanding how different hepatitis viruses spread can help families protect themselves without avoiding normal interactions.

Can You Get Hepatitis By Living With Someone?

Dr Nanda Kishore M, Gastroenterology, Athulya Geriatric Care Hospital, answers our question, "No, Hepatitis is not a communicable disease that spreads through everyday contact such as hugging, holding hands, coughing, or sneezing."

For most forms of hepatitis, the answer is no. However, hepatitis B is spread through contact with infected blood and certain body fluids. Household transmission is possible, but it generally occurs when infected blood enters another person's bloodstream.

Possible household risks include sharing:

• Razors
• Toothbrushes
• Nail clippers
• Glucose monitoring devices
• Any item contaminated with blood

Also read: Can Hepatitis Be Completely Cured? Understanding What Treatment Can Achieve

Dr. Kishore says that the mode of transmission largely depends on the type of hepatitis infected.

He says, "Hepatitis A and E are predominantly spread via means of contaminated food and water, while Hepatitis B and C are transmitted through infected blood and certain bodily fluids."

Hepatitis B is preventable by vaccine. Household members of someone with chronic hepatitis B are usually advised to get tested and vaccinated if they are not already immune.

Dr. Shalimar says, "For hepatitis B, current treatment controls the infection, and newer therapies under development offer hope for a functional cure in the future. Vaccination has dramatically reduced hepatitis B in many parts of the world. Expanding vaccination coverage remains one of the most effective ways to prevent the disease."

Living with a hepatitis infected individual is generally safe given that basic hygiene and recommended precautions are followed strictly. Understanding these facts helps reduce unnecessary fear and stigma associated with it.

Also read: Grade-1 Fatty Liver: More Indians Are Developing It at Lower BMIs. What's Behind the Shift?

Importance of Screening & Prevention

Living with someone who has hepatitis does not mean you need to keep your distance. Instead, focus on practical precautions:

• Never share personal items that may come into contact with blood.
• Cover cuts and wounds.
• Wear disposable gloves while cleaning blood spills.
• Practice good hand hygiene.
• Ensure hepatitis B vaccination if recommended.
• Attend regular medical follow-ups if advised by your healthcare provider.

Dr. Ankur Jain, Associate Director & Unit Head, Gastroenterology, Hepatology & Endoscopy, Max Hospital, Dwarka, explains, "Hepatitis B and Hepatitis C continue to affect millions of people worldwide and remain major causes of liver cirrhosis and liver cancer. Individuals with a history of blood transfusions before routine screening, unsafe injections, or other risk factors should discuss screening with their physician.

He adds, "The liver has an extraordinary capacity to heal, but only if we identify problems early and address the underlying causes. Prevention, timely screening, and simple lifestyle modifications remain our most powerful tools in reducing the growing burden of liver disease in India."