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

After Dussehra festivities, Delhi woke up to an alarming AQI of 300, maybe even more in some parts of the city. On October 21, pollution curbs under GRAP-1 were implemented, which are brought in force when AQI ranges between 201 and 300.

As Delhi's air pollution increases, some people may experience uncommon symptoms like feeling unusually tired, sluggish or unable to concentrate. This is not just a coincidence. Even people without asthma or breathing difficulties can feel fatigue, especially during periods of high air pollution.

Fine particulate matter (PM2.5) can penetrate deep into the lungs and trigger inflammation and physiological stress. Its effects may extend beyond the respiratory system, affecting blood vessels health, cardiovascular function as well as sleep.

HeathandMe spoke to Dr Puneet Khanna, Chairman, Respiratory Medicine and Pulmonology, Manipal Hospital Dwarka, New Delhi, Dr. Puneet Gupta, HOD - Pulmonology, Intervention Pulmonology & Sleep Medicine, Yatharth Super Speciality Hospital, Noida Extension, and Dr Mrinal Sircar, Director, Respiratory and Sleep Medicine, Medanta, Noida, who explained why rising AQI can leave some people feeling exhausted, what can help and when chronic fatigue needs medical attention.

High AQI May Make You Feel Tired Even Without Breathing Problems

Poor air quality does not affect just the lungs. Dr Sircar explains that air pollution can cause symptoms even in people without a pre-existing respiratory condition.

According to Dr Khanna, exposure to PM2.5 can trigger inflammation and oxidative stress, increase the body's workload and affect sleep quality. These changes may contribute to tiredness, headaches, low energy and reduced concentration, even in people with otherwise healthy lungs.

“Exposure to polluted air may also affect sleep quality and increase the body's overall stress response, contributing to symptoms such as tiredness, reduced energy and difficulty concentrating,” he says.

Dr. Gupta delves deeper into the process of PM2.5's attack and how the body responds to it.

He explained, "Your immune system treats fine particles (PM2.5) as intruders and mounts a constant low-grade defence, which burns energy much like a mild infection. At the same time, irritated airways and gases like carbon monoxide can make oxygen delivery slightly less efficient. The most underrated cause is sleep: a dry throat, blocked nose, and mild night-time cough fragment your sleep, so you wake up unrefreshed without knowing why. Fatigue here doesn’t mean your lungs are weak. It means your body is working overtime quietly."

Also read: Sky Turns Orange In Indonesia: How Toxic Smog From Wildfires Can Impact Health

Can PM2.5 Affect The Heart And Blood Vessels Too?

PM2.5 particles are small enough to penetrate deep into the lungs. Some of its components can even enter the bloodstream. Exposure can trigger inflammatory and oxidative stress responses beyond the respiratory system.

Dr Khanna says, “These changes may reduce physical endurance, increase feelings of fatigue, and contribute to symptoms such as brain fog, lethargy, and reduced exercise tolerance, particularly during periods of severe air pollution.”

Dr. Gupta explained PM2.5 can create the same response from body as a common flu does. But the extent of these effects depends on pollution levels, duration of exposure and individual risk.

He said, "PM2.5 is small enough that it, or the inflammatory chemicals it triggers, can enter the bloodstream. Signalling molecules such as IL-6 and CRP then travel through the whole body and produce the same “wiped out” feeling you get with the flu."

He also said that particles also create oxidative stress, which damages mitochondria, the power plants of your cells. Blood vessels become stiffer, blood pressure can rise slightly, and the nervous system’s control of heart rhythm can be disturbed, which may feel like heaviness or palpitations. Inflammation can also reach the brain, causing fog and poor focus.

Also read: Delhi Smog: Can You Really Tackle Pollution Season With An N95 Mask And Air Purifier?

What Can Help?

According to the doctors, the key is to reduce exposure to polluted air. Practical steps include:

• Limit exertion: Avoid strenuous outdoor activity when pollution levels are high, especially during periods of severe pollution.
• Wear a well-fitting N95 respirator: It can reduce exposure to fine particles when outdoors.
• Improve indoor air quality: Keep windows closed when outdoor air quality is poor and use a suitably sized air purifier with a HEPA filter where feasible.
• Maintain basic health routines: Get adequate sleep, stay hydrated and eat regular meals.
• Check AQI levels: Use local air quality updates to plan outdoor activities.

Dr Khanna emphasises that these steps can help reduce exposure but cannot eliminate the effects of ongoing pollution. He also said that severe breathlessness, chest pain, fainting or sudden weakness requires urgent medical attention.

Does Pollution-Induced Fatigue Go Away When AQI Improves?

For many otherwise healthy people, symptoms can improve once air quality improves. Dr Khanna says recovery may occur within a few hours to several days, depending on pollution severity, exposure duration and individual health.

However, there is no fixed recovery timeline. People with underlying respiratory or cardiovascular conditions may take longer to recover, while persistent tiredness may point to another health problem.

Dr Sircar advises seeking medical advice if fatigue continues after air quality improves.

The doctors also advise that if fatigue is chronic, recurrent, worsening or interferes with daily activities, medical evaluation should be sought rather than simply attributing it to air pollution.

Dr Sircar also says that that a doctor may need to investigate other possible causes, including anaemia, thyroid disorders, sleep problems and cardiovascular conditions. Fatigue accompanied by a chronic cough, wheezing, breathlessness, chest problems or reduced exercise tolerance also needs intervention.

A single photograph of someone’s face might carry real clues about their health and how long they’re likely to live, at least according to new AI tools built by researchers at Mass General Brigham in Boston.

What the researchers built

The team trained a large AI foundation model called FAHR-Face, short for Foundation Artificial Intelligence for Health Recognition, on more than 40 million facial images.

From that base model, they built two specialised tools: FAHR-FaceAge, which estimates a person’s biological age from a single photo, and FAHR-FaceSurvival, fine-tuned on 34,389 photos of cancer patients to predict survival risk directly from facial appearance.

“I was pretty surprised to find out that we could pick up signs of mortality risk from just a facial photograph,” corresponding author is Dr. Raymond Mak, a radiation oncologist at Mass General Brigham Cancer Institute told CNN. The study is published in The Lancet Digital Health.

What the two tools actually look at

The two algorithms focus on entirely different parts of the face. “The age estimation algorithm is looking at the area around the temples, the area on the forehead, above the eyes and then what we call the nasolabial fold,” Mak said, while “the mortality risk prediction algorithm is looking at a totally different part of the face... the bridge of the nose and the area under the eyes.”

Also Read: ADHD Linked To 71% Higher Risk Of Death; Suicide And Injuries Among Top Concerns

The results

Among 122 cancer patients flagged by FAHR-FaceSurvival as high-risk, 52.5% died within 90 days, compared with about 2% of the 975 patients in the lowest-risk group. Separately, 21% of patients whose biological age came back more than 20 years older than their actual age died within 90 days, against about 6% of those whose biological age was at least 10 years younger than their chronological age.

The researchers also found that cosmetic changes, including surgery, Botox, or makeup, didn’t throw off the models’ performance, according to the Mass General Brigham release.

An eerie echo of ancient medicine

The facial regions both AI models rely on, the nose, temples, and the area around the eyes, closely match what the Greek physician Hippocrates described around 400 BC in his Book of Prognostics as signs of approaching death: “the nose sharp, the eyes sunken, the temples fallen in.”

Mak told CNN the algorithms had no exposure to Hippocrates’ text and were trained purely on photographs and outcomes data. “Hearing Hippocrates echo over millennia in our algorithms was very eerie,” he said.

Not ready for the clinic yet

Outside experts urged caution. Dr. Wilbur Lam of Emory University, who wasn’t involved in the study, called it “an extremely compelling study” with robust associations, but said its “true clinical utility... will need to be demonstrated prospectively,” and flagged open questions about how well it performs across different facial features, skin tones, and age groups.

Miroslaw Bober of the University of Surrey, also not involved in the study, said the findings shows “convincing evidence” of a statistical link but cautioned that “predicting an outcome is not the same as explaining it.”

He noted the study never tested whether the AI model picks up anything a doctor’s own assessment wouldn’t, since doctors’ general health evaluations weren’t measured for comparison. “This is a promising proof of concept, but it is not ready for clinical use,” Bober said.

An individual's income, education, gender and place of residence can impact their risk of developing chronic diseases, as well as their access to diagnosis and treatment, according to a new World Health Organization (WHO) report.

The report highlights how social and economic inequalities affect the burden of noncommunicable diseases (NCDs) like cancer, cardiovascular diseases, diabetes and chronic respiratory diseases.

Published on October 20, State of Inequality: Noncommunicable Diseases and Their Risk Factors is WHO's first comprehensive global assessment of inequalities in NCDs and their risk factors. The report is based on data sources from nine countries and examines 35 indicators, using national data that collected over the past decade.

NCDs account for about three-quarters of deaths worldwide but their impact is not shared equally across different countries and their populations. The report examines how differences in economic status, education, sex, age, disability, employment, migration status and location influence disease risks and access to healthcare.

“This is the first effort to systematically measure inequalities in NCDs and their risk factors on a global scale,” said Dr Ahmad Reza Hosseinpoor, who leads WHO's health inequality monitoring team. “The findings show which populations are being left behind.”

How Income And Education Influence Chronic Disease Risk

The report found that people with lower levels of education in low and middle income countries tend to have higher rates of hypertension and diabetes.

Education can affect access to credible health information, opportunities to make informed health decisions and the capability to navigate technically complex healthcare services.

Income becomes a key factor that affects whether people's ability to afford nutritious food, preventive care, medicines and routine medical check-ups.

The report found that the poorest and least-educated women were less likely to receive cervical cancer screening. Tobacco use was also higher among men who were less educated than their educated counterparts.

Also read: G155E H1N1 Mutation In US Raises Concerns: Can This Year’s Flu Shot Still Protect You?

Risk Is Also Affected By Gender And Location

Differences in healthcare access and risks were also observed between men and women. Men were more likely to use tobacco and consume alcohol, but men with hypertension were less likely to be diagnosed and treated than women.

Women were less likely to meet recommended physical activity levels, while obesity was more common among women, particularly in low and middle-income countries.

Geography was another key factor as in many underprivileged countries, people living in rural areas had less access to hypertension diagnosis and treatment, as well as cervical cancer screening.

Rural households could also face greater exposure to household air pollution, while urban populations often experienced greater exposure to outdoor air pollution.

People with disabilities and migrants may also face financial, administrative, geographical or language barriers that make prevention, screening and treatment harder to access.

Also read: Lead Poisoning: WHO Warns There Is No Known Safe Level; Flags Risks From Paint, Spices and Cookware

What Needs To Change According To WHO

WHO said countries should use inequality data to identify marginalised populations who face barriers to enable direct prevention and treatment services towards them.

The report recommends expanding interventions to reduce NCD risks, improving access to screening and treatment in weak communities, and collecting data that reveal differences between population groups.

“Inequality data are not simply about documenting differences – they are a tool for action,” said Dr Alain Labrique, director of WHO's Data, Digital Health, Analytics and AI Department. “They help countries better tailor policies and programmes, identify gaps in coverage and track whether progress is reaching all population groups.”