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

Four-year-old Deborah started school this year full of excitement. But she is struggling to understand why she now has to attend classes on a screen. The nursery student misses the school bus, chatting with friends and running around the classroom. Despite the appeal of screens, she finds it difficult to sit still for online lessons.

Coughing badly, she asks what pollution is and pleads with her family to let her play in the park.

Deborah is not alone. Across Delhi-NCR, children are facing similar disruptions as schools shift classes online amid deteriorating air quality, keeping them indoors for longer.

Air pollution in India is no longer just a winter problem. Although levels peak during the colder months, poor air quality has increasingly become a year-round concern, with Delhi-NCR experiencing severe pollution episodes.

Beyond its well-documented respiratory and developmental effects, pollution and the disruption it brings to children's daily lives may also affect their emotional well-being. HealthandMe spoke to health experts, who warned that reduced outdoor play, disrupted social interactions and increased screen time could add to children's psychological stress.

How Air Pollution Can Affect Children's Mental Health

Air pollution should not be viewed as an isolated exposure when examining its impact on children's mental health, said Dr. Pradeep B.S., a Professor of Epidemiology and Deputy Medical Superintendent at the National Institute of Mental Health and Neuro Sciences (NIMHANS) in Bengaluru.

"Air pollution is a macro-level effect. If we reduce it to individual-level effects, we are scientifically wrong," he told HealthandMe on the sidelines of the 11th Together Against Stigma (TAS) Conference, held in the national capital.

He said air pollution is associated with several broader changes, including increased traffic, population growth, climate disturbances and unpredictable weather patterns. Together, these can have a silent effect on people's psychological well-being, including that of children and adolescents.

The effects may not always be direct. Respiratory and gastrointestinal problems, for instance, can prevent children from going outdoors and participating in activities. Losing the opportunity to play can itself become a source of distress.

He also pointed to urbanisation and road expansion, which not only contribute to pollution but also reduce green spaces, playgrounds and community recreational areas. The combination can limit children's opportunities to play, interact and socialise.

Environmental Stress Can Also Affect Children's Emotional Well-Being

Dr. Pallab K. Maulik, the Director of Research at The George Institute for Global Health India said air pollution is one of the contributors to mental health concerns, with both Indian and international research examining the association.

He told HealthandMe that pollution and environmental disasters can create anxiety and stress among children, particularly those whose everyday lives are disrupted by these conditions.

Citing an example from one of his study sites, he recalled speaking to a child living in a slum area whose home gets flooded whenever municipal tankers wash the streets. The child has to spend two days drying her books after the water enters the house.

Dr Pallaub also referred to children in the Sundarbans who regularly experience flooding and salinity-related problems.

He said some adolescents are now using platforms such as adolescent parliaments to bring their concerns to local administrators. While children are becoming more aware of environmental challenges, he said, much more needs to be done to understand how environmental changes affect their mental health.

Staying Indoors, Screen Addiction And Anxiety

Dr Syed Hubbe Ali - Health Specialist (RMNCHA) at UNICEF highlighted another possible consequence of pollution-related restrictions on outdoor activities: increased screen exposure among children and adolescents.

When children cannot go outside, they tend to spend more time indoors, often turning to mobile phones, social media and online content. This can create a cycle of screen dependence, he explained.

He described how the pursuit of dopamine, associated with the brain's reward system, can encourage children to keep scrolling through social media content.

The cycle can become more complicated when children begin posting content and seeking validation through likes and engagement.

"Once you start developing your roles, the next stage comes when you see how many likes I got. I got the likes, I don't get the likes. Then the anxiety, you know, it starts," Dr Ali told HealthandMe.

He explained that not receiving the expected engagement can cause distress and, in some cases, contribute to depressive feelings and risky behaviour.

Dr Ali also raised concerns about children spending more time on screens for online learning. Referring to an NCERT survey conducted after the COVID-19 pandemic among 3.7 lakh children, he said only 51% were able to understand online content.

He suggested that learning methods need to move beyond conventional online teaching and incorporate more games and interactive approaches to improve children's engagement.

Why Outdoor Play And Social Spaces Matter

Dr Pradeep emphasised that the impact of pollution cannot be separated from the wider changes taking place in children's surroundings.

Reduced access to green spaces and recreational areas can affect opportunities for physical activity, social interaction and play. When children are unable to participate in these activities, the effects can extend beyond physical health.

Dr Ali also highlighted the importance of outdoor activities and sunlight exposure in children's everyday lives. He said keeping children indoors for prolonged periods can increase their dependence on digital platforms as a source of entertainment and stimulation.

Gait, or an individual's walking pattern, is an important marker of overall health, reflecting neurological integrity, musculoskeletal function and cognitive status. Although walking may seem effortless, people often dismiss changes in their gait as signs of tiredness or ageing.

Losing balance while walking can sometimes be attributed to fatigue, dehydration or a momentary lapse in attention. However, recurrent or unexplained balance problems can also indicate an underlying neurological condition and should not be ignored, experts warned.

Dr Gaurav Batra, Principal Consultant, Neurosurgery, Yashoda Super Speciality, said individuals experiencing instability, changes in their walking pattern or more frequent tripping than usual should seek medical evaluation.

"Walking seems so natural that it is often taken for granted. However, it involves the brain, nerves, muscles, eyes and the balance system in the inner ear working in unison," he told HealthandMe.

"When there is a disorder in one of these systems, the way a person walks can be affected, which is exactly why the type of imbalance becomes an important consideration. One person may feel like they are being dragged in a particular direction," the expert added.

When Is Loss Of Balance A Neurological Warning Sign?

New, persistent or worsening balance problems warrant attention, Dr Batra said. Changes in walking patterns or deteriorating balance could sometimes indicate an underlying problem affecting the brain or spinal cord.

Certain conditions can cause pressure on the brain or spinal cord in the neck, resulting in subtle changes in walking patterns and the ability to maintain balance.

Dr Batra advised against dismissing increasingly abnormal changes in walking, particularly when they affect daily activities or occur alongside stiffness, tremors, weakness, numbness or difficulty with coordination.

Neurological Conditions That Can Affect Balance

Dr Atampreet Singh, Senior Director and Head, Institute of Neurosciences, ShardaCare - Healthcity, explained that disruptions in the systems responsible for maintaining balance can cause unsteadiness, difficulty walking in a straight line, frequent stumbling and an increased tendency to fall.

Recurrent balance problems may be associated with several neurological conditions, including:

• Parkinson's disease: Can affect movement and coordination, making walking and maintaining balance difficult.
• Cerebellar disorders: Can interfere with coordination and the ability to maintain a steady gait.
• Peripheral neuropathy: Damage to peripheral nerves can affect sensation and balance.
• Multiple sclerosis: Can disrupt communication between the brain and the rest of the body, affecting coordination and walking.

In older adults, recurrent or unexplained falls may sometimes be an early indication of an underlying neurological or sensory deficit, Dr Singh told HealthandMe.

Sudden Loss Of Balance Could Indicate A Stroke

A sudden loss of balance, particularly when accompanied by other neurological symptoms, can be a warning sign of stroke and requires immediate medical attention.

Dr Singh highlighted the following symptoms to watch for:

• Weakness or numbness on one side of the body
• Facial weakness
• Difficulty speaking
• Severe dizziness
• Visual disturbances
• A sudden, severe headache

Such symptoms require immediate medical assessment, the expert noted.

When Should You See A Doctor?

Seek medical attention if unsteadiness persists or worsens, particularly when accompanied by weakness or numbness in the arms or legs, frequent falls, severe headache, vomiting, changes in vision or speech, or loss of bladder or bowel control.

A doctor may conduct a neurological examination and recommend brain or spinal imaging, if necessary, to determine the cause.

The doctors noted that early diagnosis is important because some underlying conditions are treatable, and timely intervention may help prevent permanent neurological problems.

They advised patients to pay attention to when the imbalance began, whether it appeared suddenly or developed gradually, and whether it is accompanied by tremors, dizziness, numbness, weakness, speech changes or difficulty with coordination.

When we talk about cancer prevention, the conversation usually turns to individual choices. Whether someone smokes, what they eat, how much they exercise, or how regularly they visit a doctor. These are important considerations, but they do not tell the whole story. A person's surroundings can influence their health in ways that are not always immediately apparent. The air they breathe every day, the conditions in which they work, the food they can afford and the healthcare available to them can all have a bearing on their risk of developing cancer.

In clinical practice, cancer rarely has one identifiable cause. It develops through a combination of factors, including age, genetics, infections, lifestyle and environmental exposure. Some of these can be modified. Others are tied to circumstances that people have little control over.

The air we breathe and the work we do

Air pollution is generally discussed in the context of respiratory and cardiovascular illness. Its association with cancer, particularly lung cancer, deserves equal attention. Fine particulate matter from vehicle exhaust, industrial emissions, construction dust and waste burning can remain in the air people breathe over long periods. Indoor air quality is another concern. In homes where wood, coal or other biomass fuels are used for cooking, poor ventilation can expose families to harmful smoke over many years.

The workplace presents a different set of risks. Construction workers, miners and employees in certain manufacturing industries may regularly come into contact with substances such as asbestos, silica dust and diesel exhaust. Prolonged exposure to these carcinogens is associated with specific cancers. The risk is not simply a matter of the nature of the job, but also the conditions under which it is performed. Protective equipment, adequate ventilation and routine workplace monitoring are therefore essential, not optional safety measures.

What ends up on the plate is not always a choice

Diet is another area where personal circumstances matter. What a person eats is influenced by affordability, availability, working hours and household responsibilities. A consistently poor dietary pattern, particularly one high in processed meat and low in fibre, is associated with an increased risk of certain cancers. Excess body weight is also linked to several cancers, including colorectal, endometrial and postmenopausal breast cancer.

This does not mean that eating a particular food will cause cancer, or that avoiding one ingredient will prevent it. The concern is with patterns that develop over time, alongside other risk factors. Advising people to eat better is only useful when that advice considers what they can realistically afford and access.

Why some communities face greater challenges

The same health advice does not translate into the same opportunities for everyone. People living in congested neighbourhoods may have limited control over their exposure to pollution. Workers in informal or unregulated sectors may not have access to adequate protective equipment or occupational health services.

These circumstances can also determine how quickly someone receives a diagnosis. A persistent cough, unexplained weight loss, a breast lump or unusual bleeding may initially be dismissed. For someone who has to travel long distances, lose a day's wages or pay out of pocket for investigations, seeking medical attention is not always straightforward. By the time they reach a specialist, the disease may have progressed.

Early detection, therefore, is not just about recognising symptoms. It also depends on whether people can access a doctor, undergo the necessary investigations and complete their follow-up care.

Prevention has to go beyond individual choices

There are established ways to reduce cancer risk. Avoiding tobacco, limiting alcohol, maintaining a healthy weight and staying physically active all matter. HPV and hepatitis B vaccination can help prevent cancers associated with these infections. Screening for breast, cervical and oral cancers should be undertaken as recommended, based on age and individual risk. A persistent or unusual symptom should always be evaluated rather than left unattended.

But prevention cannot stop at the doctor's consultation room. Cleaner air, safer workplaces, better housing and affordable diagnostic services need to be part of the larger conversation.

A person's risk of cancer is shaped by more than the choices they make. It is also influenced by the conditions in which they live, work and seek care. Recognising this is important because prevention becomes meaningful only when people have a fair opportunity to act on it.

(Dr Rajesh Shinde - Director – GI (HPB–Colorectal) & Thoracic Surgical Oncology, Apollo Cancer Centre, Western Region, Apollo Hospitals)