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

Leptospirosis gained attention after its cases surged in Kerala recently. The infection has also been reported in Maharashtra, Gujarat, Tamil Nadu, and Karnataka. The bacterial infection typically spreads via contact with water or soil that has been contaminated by the urine of animals infected with leptospirosis, especially during floods.

As monsoons are right at our doors, know why it is important to detect and nab dangerous infections like leptospirosis early.

What Is Leptospirosis?

Leptospirosis is a potentially serious bacterial infection sometimes called the "rat fever" because it can cause symptoms similar to the typical symptoms of common viral infections, which may not be noticeable in the early stages. It is caused by the bacteria of the genus Leptospira that are excreted in the urine of infected animals, including rats, cattle, dogs, and pigs.

In the monsoon season, there is a risk of waterlogging and contaminated animal urine mixing with floodwater and soil. Infestation occurs through direct contact with contaminated water or mud on cuts or abrasions or on the mucous membranes of the mouth, nose, and eyes. Those involved in outdoor work, sanitation, farming, construction, or who are walking in flooded streets are especially at risk.

Combating Leptospirosis In Monsoon

Health and Me spoke to Dr. Sundar Krishnan, Senior Consultant - Internal Medicine, KIMS Hospital, Thane, about how to tackle leptospirosis this monsoon.

Dr. Krishnan says, “In the early stages, it may have flu-like symptoms, and that makes early recognition challenging. Symptoms are sudden onset of high fever, chills, very severe headache, muscle pain especially in the calves and lower back, fatigue, nausea, vomiting, and red eyes.”

The expert also said that occasionally, the patient may also have abdominal pain or diarrhea. He also says it can escalate quickly to jaundice, kidney failure, difficulty breathing, meningitis, internal bleeding, or multi-organ failure and can require immediate medical care.

Dr. Krishnan recommends several prevention tips to tackle leptospirosis in monsoon:

• Avoiding contact with contaminated water by staying out of flooded areas whenever possible.

• Wearing waterproof boots and gloves for extra protection.

• Covering cuts or wounds with waterproof dressings before entering flood water.

• Maintaining good personal hygiene, washing hands and feet extensively after contact with flooded and stagnant water.

• Getting out of wet clothes as soon as possible.

• Taking measures for proper waste disposal to control rat infestation.

• Raising awareness and educating the public about the risk of leptospirosis during the rainy season.

If leptospirosis is diagnosed early and treated with antibiotics, recovery is much quicker, avoiding life-threatening complications. But if detection and treatment are delayed, the kidneys, liver, lungs, and even the brain may be affected.

The expert advises that people who are ill after being exposed to flood water and are facing fever or flu-like symptoms for more than two days should also seek medical help as soon as possible, informing their doctor about their flood water exposure.

Even though the risk of leptospirosis is high during the monsoon, the best way to steer clear of this infection is to educate the masses about its symptoms and prevention. Early clinical intervention can help de-escalate the situation promptly.

Headaches are one of the most common health complaints and are often caused by stress, lack of sleep, dehydration, excessive screen time, skipped meals, or other lifestyle factors. While most headaches are benign, experts said that frequent or unusual headaches should not be ignored, as they may signal an underlying medical condition that requires evaluation.

The experts told HealthandMe that paying attention to changes in headache frequency, pattern, and associated symptoms can help identify when medical attention is necessary.

Increasing Frequency Is a Warning Sign

According to Dr. Rajneesh Kummar, Vice Chairman & Unit Head, Neurology, Max Super Speciality Hospital, Dwarka, one of the most common concerns is increasing frequency.

“If someone who previously experienced occasional headaches starts getting them several times a week or finds that painkillers are needed more often than before, it is worth getting evaluated,” he told HealthandMe.

“People should seek medical attention if they have headaches more than 10 to 15 days a month, if the headaches are getting worse, or if they are beginning to interfere with work, daily activities, or quality of life,” added Dr. Praveen Gupta, Chairman, MAIINS, Marengo Asia Hospitals, Gurugram. He also noted that medication-overuse headaches can result from taking painkillers regularly, leading to a cycle of recurrent pain.

Also read: Shingles Vaccine May Help Fight Dementia, Suggest Studies

Watch For Changes In Headache Pattern

A change in the pattern of headaches should not be ignored. Dr. Kummar said a headache that feels different from what a person has experienced in the past, particularly after the age of 50, deserves medical attention. Headaches that wake a person from sleep, are worse in the early morning, or are associated with vomiting should also be assessed further.

Dr. Gupta advised prompt medical evaluation for people over the age of 50 who develop a new type of headache. He also recommends seeing a doctor if a person has a history of cancer, a weakened immune system, or develops a headache after a head injury.

Symptoms That Need Immediate Medical Attention

The neurologists highlight several "red flag" symptoms that require urgent medical assessment. They advised immediate consultation if a headache is accompanied by

• weakness on one side of the body,
• difficulty speaking,
• double vision,
• confusion, seizures,
• loss of consciousness,
• Numbness
• balance problems

Read More:Sepsis: India Joins Global Trial To Screen Newborns For Deadly Drug-Resistant Infections

Not Every Headache Is a Brain Tumor

Dr. Kummar stated that many people worry that every headache is related to a brain tumor or another serious brain disorder. Fortunately, this is rarely the case.

However, persistent or unusual headaches should not be self-diagnosed, and timely consultation helps identify the cause and ensures appropriate treatment before the problem begins affecting quality of life, the expert said.

Early Diagnosis Key

Dr. Gupta told HealthandMe that early diagnosis can help manage common neurological disorders such as migraines, cluster headaches, and chronic tension-type headaches. A thorough history, neurological examination, and imaging studies, when appropriate, can help determine the cause.

The experts emphasize that if headaches are becoming more frequent, changing in patterns, or affecting daily life, it is time to consult a neurologist. Early diagnosis can provide relief, prevent complications, and improve overall quality of life.

Several recent studies suggest that older adults who receive the shingles vaccine may be less likely to develop dementia, a condition affecting more than 57 million people worldwide.

Shingles is a painful viral infection caused by the reactivation of the varicella-zoster virus (VZV), which can remain dormant after chickenpox and later trigger a blistering rash and severe nerve pain.

Shingrix Vaccine And Reduced Dementia Risk

A June 2026 study published in the Annals of Internal Medicine suggests that one in 17 dementia cases could potentially be prevented through shingles vaccination.

Researchers at Brown University found that older adults who received the recombinant shingles vaccine (Shingrix) after a stay in a skilled nursing facility had a 24% lower risk of being diagnosed with dementia over four years than those who were not vaccinated.

The study analyzed Medicare and health records from more than 500,000 adults aged 66 and older admitted to skilled nursing facilities. Researchers compared those who received at least one dose of Shingrix with those who remained unvaccinated.

“A lot of previous studies with similar results focused on an older vaccine,” said study author Kaley Hayes, an assistant professor at Brown University’s School of Public Health.

“This study looks at the newest vaccine only in an older, vulnerable adult population who were not up to date with shingles vaccination and are at a very clear clinical point in care: entering a skilled nursing facility.”

The findings add to growing evidence linking shingles vaccination with a lower risk of dementia.

Also read: How To Spot Leptospirosis, Dengue, Malaria During Monsoons? Early Symptoms Not To Neglect

How Does The Vaccine Protect The Brain?

Researchers believe the vaccine may help protect the brain by preventing shingles and the inflammation caused by the virus.

Shingles can cause a “war zone” of inflammation in the brain, said Dr. Jennifer Pauldurai, the medical director of the Inova Brain Health and Memory Disorders Program in Northern Virginia, NBC News reported.

It’s not that the shingles vaccine itself is a “magic pill,” Pauldurai said.

Rather, the vaccine guards against the disease, which is known to disrupt brain health.

Evidence from Wales, Australia, and Canada

The latest findings add to a growing body of international research.

A study involving more than 282,000 older adults in Wales, published in Nature in 2025, found shingles vaccination was associated with a 3.5% lower absolute risk of dementia over seven years.

Another study of more than 101,000 older adults in Australia, published in the Journal of the American Medical Association in 2025, found vaccine eligibility was associated with a 1.8% lower dementia risk over 7.4 years.

Similarly, a study involving more than 232,000 older adults in Canada, published in The Lancet Neurology in 2026, linked shingles vaccine eligibility to a 2% lower dementia risk over 5.5 years.

Read More: Sepsis: India Joins Global Trial To Screen Newborns For Deadly Drug-Resistant Infections

Shingles: Early Warning Signs

After a person recovers from chickenpox, the VZV virus remains dormant in nerve cells and can become active again years or even decades later, particularly when the immune system weakens.

Older adults and people with weakened immune systems are at the highest risk of developing shingles.

According to the NHS, shingles often starts with:

• Burning, tingling, itching, or pain on one side of the body
• Headache or feeling generally unwell
• A blistering rash that develops within a few days, most commonly on the chest or abdomen

When To See A Doctor

Seek prompt medical attention if:

• The rash appears on or near the eye
• The pain is severe or rapidly spreading
• You have a weakened immune system
• You are pregnant
• Symptoms are worsening quickly