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

Women's bodies have long been understudied, and even a simple touch can trigger unexpected sadness, anguish or homesickness. One such experience is Sad Nipple Syndrome (SNS), which many women may experience without knowing it has a name. Triggered by nipple stimulation, it remains poorly understood and largely unresearched.

Some describe it as sudden sadness or anguish, while others compare it to homesickness, nostalgia or an upsetting memory. Even putting on a shirt can trigger the sensation.

SNS is not an officially recognised medical diagnosis. Although it can affect anyone, it appears more common in women, according to the Cleveland Clinic.

Sad Nipple Syndrome Can Begin In Childhood

Also read: Lessons From The Lindsay Clancy Case: Can Families Spot Early Signs Of Postpartum Psychosis?

Some people experience SNS from childhood without understanding what is happening.

“I was probably a child when I first noticed: ‘Why does touching my nipple make me sad?’” 28-year-old Sandra told The Guardian.

She kept the experience to herself until college, when she searched for answers online. “I realized I wasn’t crazy,” she said.

The Role Of Oxytocin And Dopamine

One possible explanation involves oxytocin, commonly known as the 'love hormone'.

Dr Vladimír Kraus from the Department of Gynaecology and Obstetrics at Pavol Jozef Šafárik University suggests oxytocin may be involved because nipple stimulation triggers its release.

Oxytocin plays a role in bonding and emotional connection. It is released during physical touch and also plays a role in childbirth and breastfeeding.

Kraus theorises that changes in oxytocin signalling could trigger negative emotions associated with SNS, although this has not been established.

A study found that breast stimulation increased oxytocin levels in both lactating and non-lactating women, suggesting the response is not limited to breastfeeding.

Maureen Sweeney, a psychiatric mental health nurse practitioner and women's behavioural health specialist at the Cleveland Clinic, suggests oxytocin release may also influence dopamine production. Reduced dopamine could contribute to dysphoric feelings, although this remains a proposed explanation.

Other possible factors include postpartum mental health, body image concerns, anxiety and intimate partner violence. Sweeney also points to premenstrual dysphoric disorder (PMDD), suggesting that some people may be more sensitive to normal hormonal fluctuations.

Read More: Breastfeeding Can Help Reduce Mothers' Risk of Type 2 Diabetes, Breast Cancer and More

How Is SNS Similar To D-MER And Post-Coital Dysphoria?

Dysphoric milk ejection reflex (D-MER) causes sudden negative emotions, such as sadness, homesickness and guilt, just before or during milk letdown while breastfeeding. It can also affect the breastfeeding experience and maternal bonding.Post-coital dysphoria (PCD), meanwhile, involves sadness, anxiety or irritability after sexual activity.

While SNS and D-MER are associated with nipple stimulation, PCD occurs after orgasm. Despite the different triggers, people can experience similar emotional and physical sensations, lactation consultant Alia Macrina Heise was quoted as saying to The Guardian.

She suggested hormonal interactions may be involved in all three conditions, although their precise mechanisms remain unclear.

Is There A Treatment For Sad Nipple Syndrome?

There are no specific treatments for SNS, and more research is needed to understand its causes. However, coping strategies and psychological support may help manage the distress. Sweeney suggests cognitive behavioural therapy (CBT) as one approach to addressing symptoms, even when a therapist is unfamiliar with SNS.

Per- and polyfluoroalkyl substances (PFAS), commonly known as forever chemicals, have sparked interests of epidemiologists who are investigating their links to chronic diseases like high blood pressure, cardiovascular conditions and certain cancers.

PFAS are a large group of chemicals made by humans that have been used in industrial processes and everyday consumer products. They are found in cosmetics, kitchen supplies, clothing, carpets, upholstery, food packaging and other household materials.

They are called forever chemicals because their strong chemical bonds make them resistant to breaking down in the environment. Some PFAS can also exist in the human body, allowing exposure to accumulate over time.

At the American Public Health Association's (APHA) 2026 Annual Meeting, researchers presented findings on how people are exposed to these chemicals everyday through food and drinking water, and what long-term health consequences may be related to that exposure.

Health Problems Linked To Forever Chemicals

Some studies have identified that PFAS exposure could lead to colon and liver cancers, low birth weight, development problems in children, complications during pregnancy and other metabolic disorders. Research has also identified its exposure to cholesterol, changes in liver enzymes, reduced antibody responses to some vaccines and hypertension during pregnancy.

However, this does not establish that PFAS exposure directly causes every condition reported in epidemiological studies. Health effects may depend on the chemical type, exposure levels, duration of exposure and individual factors.

The US Agency for Toxic Substances and Disease Registry (ATSDR) states that research into PFAS health effects is in progress.

Also read: Paper Straws Have 6.33 Times Higher Carcinogenic Risk Than Plastic Straws, Study Finds

Food Is A Significant Source Of PFAS

Besides drinking water, food can also contribute to exposure, prompting researchers to investigate whether dietary habits influence the relationship between PFAS and chronic health conditions.

One study conducted in Massachusetts examined the relationship between dietary patterns, PFAS exposure and blood pressure. Researchers found stronger associations between a specific PFAS compound and high blood pressure among people who regularly consumed fish.

Yuting Wang, a postdoctoral research fellow at Silent Spring Institute and one of the researchers involved in the study, said animal-based foods appeared to contain more PFAS than plant-based foods.

One possible explanation, she suggested, was that meat consumption could increase inflammation, which may influence the relationship between PFAS exposure and blood pressure.

"Better understanding interactions among diet, PFAS and blood pressure may improve clinical recommendations to prevent hypertension," Wang said. "Future studies should account for exposure to environmental pollutants in addition to nutrient benefits of certain food," she added.

Also read: Lancet Study Finds Air Pollution & Chemical Exposures Could Add To South Asia's Diabetes & Heart Disease Burden

PFAS Found In US Drinking Water Supplies

According to the US Geological Survey, approximately 45% of drinking water samples collected across the country showed traces of PFAS. Researchers have also investigated PFAS contamination in 11 townships in southeastern Pennsylvania. Their testing found that several drinking water supplies had PFAS concentrations exceeding the US Environmental Protection Agency's 2021 regulatory limits.

The team also examined two decades of mortality data from the townships to investigate whether areas with higher PFAS levels in public drinking water has different patterns of disease and death.

Erin Kulick, an assistant professor of epidemiology and biostatistics at Temple University College of Public Health who worked on the Pennsylvania study, said, "Southeastern Pennsylvania experiences overlapping burdens of PFAS exposure and cardiovascular disease."

Scientists Are Concerned About Long-Term Exposure

PFAS contamination is a public health concern because these chemicals can remain in the environment for long periods and reach people. Some PFAS accumulate in the body, and repeated exposure may increase the amount present over time.

The National Institutes of Health identifies several health concerns linked with exposure to certain PFAS, including immune system effects, increased cholesterol, liver changes, pregnancy-related complications and some cancers.

The US Environmental Protection Agency has established legally enforceable drinking water limits for six PFAS compounds, including perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS).

Researchers say more comprehensive monitoring, better assessment and long-term epidemiological studies are needed to understand how PFAS contamination affects communities.

A simple five-factor risk score may help identify people at high risk of dementia, particularly in low- and middle-income countries (LMICs), where around 60% of the world's dementia cases now occur.

Developed and validated by researchers at Northumbria University, the risk score uses five everyday factors to identify older adults at higher risk of dementia. It aims to address a gap in dementia research, as existing prediction tools have largely been developed using data from high-income countries and may not work as well in lower-income settings.

The research team developed the model using data from more than 11,000 older adults across seven countries and three continents.

“We know the burden of dementia is shifting towards lower-income parts of the world, yet the prediction models clinicians and researchers rely on were designed with wealthier populations in mind. This model is a step towards changing that. It is simple, it is built for the settings where it is needed most, and it gives researchers a practical way to find the people who should be the focus of future studies and trials,” said Dr Eduwin Pakpahan, from Northumbria University's Applied Statistics and Data Science Research Group. The study is published in the American Journal of Epidemiology.

What Are The Five Factors Used To Predict Dementia Risk?

Also read: WHO's New Dementia Guidelines Prioritize Healthy Habits, Warn Against Supplements

The model can be applied using information gathered through a straightforward conversation with an older adult and, where relevant, a family member or carer. It does not require blood tests, brain scans or specialist equipment.

The five factors included in the risk score are:

• Age: The strongest single predictor. Dementia risk rises meaningfully from age 70 and more steeply from 80 onwards.
• Social engagement: This includes whether a person is married or living with others, how often they meet friends or family, and whether they participate in community or religious groups.
• Physical activity: The model considers how active a person is in daily life, across both work and leisure. Everyday movement, such as farming, walking to the market or doing household tasks, also counts.
• High blood pressure: Uncontrolled hypertension can damage the blood vessels supplying the brain over time. It is common, often undiagnosed in lower-income settings, and inexpensive to manage.
• Difficulty managing money: A family member or carer is asked whether the person has experienced a noticeable change in their ability to handle finances. This can be one of the early everyday signs of cognitive change.

How Does The Dementia Risk Score Work?

Each factor contributes points towards a total score ranging from 0 to 9. A person scoring 0 has around a 1% chance of developing dementia within three years, while someone scoring 9 has a nearly 19% chance.

The researchers built and tested the model across seven sites in China, Cuba, the Dominican Republic, Puerto Rico, Venezuela, Mexico and Peru. It achieved a performance score of 0.75, above the 0.70 threshold generally regarded as clinically useful.

However, the researchers emphasise that the tool is primarily intended for research rather than routine screening of the general population. It could give researchers and clinical trial teams a practical, low-cost way to identify and recruit people at higher risk of dementia.

The team has also called for the model to be validated in regions not covered by the study, particularly South Asia, the Middle East and North Africa, and Sub-Saharan Africa.

Read More: Dementia Is More Than Forgotten Birthdays, Lost Keys: Doctors Explain Early Signs Before Memory Loss

Why Is A Dementia Risk Prediction Tool Important?

Dementia affects more than 57 million people worldwide, with around 60% of cases occurring in LMICs across Latin America, the Caribbean, Asia and Africa.

Identifying people at higher risk could help researchers in these regions plan studies and clinical trials that better reflect their populations. A simple tool based on everyday information may also make risk assessment more accessible in settings where specialised diagnostic resources are limited.