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

HbA1c, also known as hemoglobin A1c or glycated hemoglobin, is a widely used blood test to diagnose and monitor diabetes. However, ahead of World Diabetes Day, experts have warned that the test may not be accurate for everyone.

HbA1c measures how much glucose is attached to hemoglobin in red blood cells, providing an estimate of average blood sugar levels over the previous two to three months.

Certain medical conditions and blood disorders can affect its accuracy, making readings appear higher or lower than actual blood sugar levels.

Who May Get Inaccurate HbA1c Results?

Conditions such as anemia and hemoglobin disorders can affect HbA1c readings by altering the lifespan of red blood cells.

"HbA1c can be misleading when conditions alter red blood cell lifespan. Iron, B12 or folate deficiency may falsely elevate HbA1c. Conversely, hemolytic anemia, certain hemoglobinopathies, chronic blood loss, recent transfusion and some kidney conditions can lower it falsely," Dr Manisha Arora, Director of Internal Medicine at CK Birla Hospital, Delhi, told HealthandMe.

Dr Sandeep Kharb, Senior Consultant – Endocrinology at Asian Hospital, added that iron-deficiency anemia can also lead to falsely high HbA1c readings.

Experts also cautioned that HbA1c is not a direct measure of insulin resistance. A person may be insulin resistant even before their HbA1c reaches the prediabetes threshold.

What Medical Conditions And Medications Can Affect HbA1c?

Iron, vitamin B12 and folate deficiencies, chronic alcohol use, high-dose aspirin and severe hypertriglyceridemia may contribute to falsely elevated readings.

Falsely low results can occur with hemolytic anemia, hemoglobin disorders, blood loss, transfusions, pregnancy, kidney disease and erythropoietin therapy.

Certain medicines, including dapsone, ribavirin and some antiretroviral drugs, can also affect HbA1c interpretation. The direction of the error depends on the underlying condition and the testing method.

Can Fasting Blood Sugar Be Normal While HbA1c Is High?

Dr Himika Chawla, Senior Consultant, Endocrinology and Diabetology at PSRI Hospital, told HealthandMe HbA1c reflects average blood sugar over two to three months, while fasting blood sugar measures glucose at a particular point in time.

A person may have normal fasting glucose but experience repeated blood sugar spikes after meals, pushing their HbA1c higher. The reverse mismatch can also occur.

Doctors therefore consider both results and the patient's overall clinical picture before making a diagnosis.

What Test Should Be Used To Diagnose Diabetes?

When HbA1c may not be reliable, doctors can use blood glucose-based tests, including fasting plasma glucose and the oral glucose tolerance test (OGTT).

"First test it should be oral glucose tolerance test," Dr Anoop Misra told NDTV.

For the test, a person eats their usual meals for three days and then fasts for eight to 10 hours before their fasting blood glucose is measured. They then drink 75 grams of glucose mixed in water, followed by another blood test two hours later.

Misra explained that fasting glucose below 100 mg/dL and a two-hour reading below 140 mg/dL are normal. Fasting levels of 100–125 mg/dL or two-hour readings of 140–199 mg/dL indicate prediabetes. Fasting glucose of 126 mg/dL or higher, or a two-hour reading of 200 mg/dL or higher, falls in the diabetes range.

A new review of studies has found that people living with type 2 diabetes have a significantly higher risk of developing Alzheimer's disease.

Researchers from Curtin University conducted a systematic review and meta-analysis of 40 studies. They estimated that if 1,000 people with type 2 diabetes were followed for a year, an average of 4.7 would develop Alzheimer's disease.

Published in Alzheimer's Research & Therapy, a separate analysis found that type 2 diabetes was associated with a 53% higher adjusted relative risk of Alzheimer's disease compared with people without the condition.

How Does Blood Sugar Affect Memory?

Ahead of World Diabetes Day, Dr Sudhir Kumar, neurologist at Apollo Hospitals, Hyderabad, in a post on X, explained that several overlapping mechanisms may link type 2 diabetes to Alzheimer's disease. These include:

• Brain insulin resistance: Brain cells become less responsive to insulin, potentially impairing their ability to use glucose for energy and clear amyloid and tau proteins.
• Vascular damage: High blood sugar can damage large and small blood vessels in the brain, increasing the risk of strokes and vascular dementia.
• Chronic inflammation: Peripheral inflammation and lipid abnormalities can weaken the blood-brain barrier and trigger neuroinflammation.

How Does Diabetes Increase The Risk Of Dementia?

According to Alzheimer's Society UK, diabetes is an established risk factor for dementia. The risk also increases with the duration and severity of diabetes. However, having diabetes does not mean a person will necessarily develop dementia.

With diabetes and Alzheimer's disease cases rising globally, understanding the link between the two conditions is becoming increasingly important.

Insulin helps regulate blood sugar by enabling the body's cells to use glucose for energy. In people with diabetes, the body either does not produce enough insulin or cannot use it effectively, causing blood sugar levels to rise.

Studies have linked type 2 diabetes to an increased risk of dementia. In people with type 1 diabetes, severe and repeated episodes of high or low blood sugar have also been associated with a higher risk.

Diabetes and Alzheimer's disease may share certain underlying mechanisms. In both conditions, brain cells can become less responsive to insulin, potentially affecting brain function and contributing to the accumulation of amyloid and tau proteins associated with Alzheimer's disease.

How Can People With Diabetes Protect Their Brain Health?

Dr Kumar recommended the following measures for people living with type 2 diabetes:

• Maintain blood sugar levels: Aim to keep glucose within your target range.
• Avoid extreme fluctuations: Prevent prolonged high blood sugar (HbA1c of 7% or higher) and severe, repeated episodes of low blood sugar (hypoglycemia).
• Manage other health conditions: Keep blood pressure and cholesterol under control.
• Prioritise a healthy lifestyle: Eat whole foods, including vegetables, fruits and whole grains, and engage in regular physical activity to improve insulin sensitivity.

"Early detection, consistent blood sugar management, and working closely with your healthcare team can help safeguard your cognitive future," he said.

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 Pallab 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.