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

Chai and pakoras are practically non-negotiable once the rains set in. For a large number of Indians, though, monsoon comes with something less welcome: a blocked nose, itchy eyes, and a "cold" that just won't quit.

Most people write this off as a seasonal cold. It's often not. A large share of the patients I see in July aren't fighting a fresh infection. They're dealing with allergic rhinitis that's been present for months at a manageable level, and monsoon has simply pushed it past a threshold they can no longer ignore.

A Bigger Problem Than It Looks

The scale of this is easy to underestimate. A national study under the Global Asthma Network, which surveyed more than 1.27 lakh children, adolescents, and adults across India, found that close to a quarter of Indian adolescents aged 13 to 14 live with allergic rhinitis. Roughly one in ten adults does too.

Other Indian research puts the overall incidence of allergic rhinitis anywhere between 20 and 30 percent of the population. This isn't a niche complaint. It's one of the more common chronic conditions walking through general practice doors, most of which are simply unnamed.

Mostly Undiagnosed, Rarely Treated Right

The same national study found something more concerning: nearly three out of four people who met the clinical criteria for allergic rhinitis had never actually been diagnosed with it. Many had lived with recurring congestion, sneezing, and disturbed sleep for years without anyone connecting the dots.

A separate survey of over 1,600 physicians across India found that while a large share see allergic rhinitis routinely in practice, more than half had never used immunotherapy, one of the few treatments that changes the course of the disease rather than just quieting it temporarily.

Why Monsoon Makes It Worse

Indian allergen-testing data show a clear rotation of triggers through the year: dust mites dominate winter, pollens dominate summer, and fungal and insect allergens rise sharply once the rains set in.

The reason is straightforward. Once relative humidity in a city climbs past 70 percent, which happens routinely through the monsoon, fungal spores and dust mites both multiply fast. Waterlogging pushes fungal spore counts up further. A damp curtain or a mattress that never quite dries between showers becomes a long-term allergen source that outlasts any single rainy day.

It Rarely Comes Alone

Allergic skin and eye conditions tend to flare with the same seasonal humidity and allergen load as allergic rhinitis, and in practice, they rarely show up in isolation. A patient with monsoon-triggered nasal symptoms is worth a closer look for coexisting asthma, eczema, or conjunctivitis, simply because in the Indian patient population, these conditions travel together more often than not.

What Actually Helps

For anyone with a known allergic condition, a few habits make a real difference once the rains arrive:

• Start early. Begin or review your antihistamine or inhaled treatment before the monsoon sets in, not after symptoms flare. Allergic inflammation is far easier to control early than to bring down once it's escalated.
• Keep the fabric genuinely dry. Bedding, curtains, and upholstery that stay even slightly damp become breeding grounds for the mold and dust mites driving most flares. Check for indoor allergens rather than just blaming obvious outdoor ones.
• Ventilate or dehumidify. Especially in bedrooms, where hours of overnight exposure do the most damage.
• Keep rescue medication accessible through the season, not just on bad days.
• Don't wait out a flare that lasts beyond a week. That's usually the point where a proper allergy workup is overdue.
• If it happens every single monsoon, that pattern itself is a diagnosis worth acting on, not just enduring.

Monsoon doesn't create new allergy patients. It reveals how well the existing ones are actually being looked after.

“Let knowledge be your shield against the changing seasons."

Even a mild case of COVID-19 may trigger long-lasting eye problems, with new research revealing that persistent inflammation and nerve damage could be responsible for symptoms that standard eye tests often fail to detect.

The study, led by researchers at Linköping University in Sweden and published in Nature Communications, sheds light on why some COVID-19 survivors continue to experience debilitating vision issues months or even years after infection.

The research began after people who had recovered from mild COVID-19 sought medical help for persistent eye complaints. Many reported:

• Severe eye pain
• Light sensitivity (photophobia)
• Difficulty reading and focusing
• Extreme eye fatigue

Many participants said the condition significantly disrupted their daily lives, preventing them from working or continuing their education.

What the Study Found

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Researchers evaluated 100 people who developed eye problems after mild COVID-19 but had never been hospitalized. Their symptoms had persisted anywhere from three months to three years.

The findings were compared with those of 32 people who had recovered from mild COVID-19 without developing eye symptoms.

Using advanced imaging and laboratory techniques, researchers identified several abnormalities that conventional eye exams failed to detect.

Persistent Inflammation and Nerve Damage

The study found evidence of:

• Long-term inflammation in the eyes
• Damage to nerves controlling multiple eye functions
• Abnormal immune activity involving T cells
• Changes in proteins found in tear fluid

Lead author Petros Moustardas, senior research associate at Linköping University, said the findings indicate that COVID-19 may trigger a severe immune reaction in the eyes, resulting in chronic inflammation and nerve dysfunction.

Why Light Sensitivity Happens

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One of the most common complaints among participants was extreme sensitivity to light. Researchers found that their pupils were allowing too much light into the eyes because of impaired nerve control.

This abnormal pupil function was also associated with:

• Headaches
• Difficulty reading
• Trouble maintaining focus

An Unusual Eye Movement Disorder

The study also identified impaired coordination between the two eyes.

Some participants developed adult-onset strabismus—commonly known as crossed eyes—a condition that is rare in adults.

Researchers believe this occurred because COVID-19 affected the nerves responsible for controlling eye muscles.

A New Way to Diagnose COVID-Related Eye Problems

Because routine eye tests often miss these abnormalities, the research team developed two diagnostic models.

The first relies on specialized ophthalmic tests available at advanced eye clinics, while the second combines these examinations with tear fluid protein analysis to improve diagnostic accuracy.

Researchers hope these models will help doctors recognize COVID-related eye syndrome earlier and pave the way for future treatments.

"We found that the problems experienced by those affected were not detectable by standard tests. We had to perform specialised examinations to detect deviations. The puzzle pieces then fell into place, and we found explanations for the symptoms," said Neil Lagali, professor of experimental ophthalmology at Linköping University.

He added that while the findings provide important clues about how COVID-19 affects the eyes, more research is needed to develop effective treatments for those living with persistent vision problems.

Plant-based Vitamin D3 is often marketed as a healthier or superior alternative to traditional supplements, but doctors say that's not necessarily the case.

According to Dr. Murtaza S. Bagwala, Head of Emergency Medical Services at Saifee Hospital in Mumbai, existing research shows that plant-based Vitamin D3 is just as effective as conventional Vitamin D3 in increasing the body's vitamin D levels.

"Current evidence suggests that plant-based Vitamin D3 performs similarly to conventional Vitamin D3 supplements. For people who prefer vegan or plant-based products, it is a suitable alternative," he told HealthandMe.

Echoing this view, Dr. Sudhir Kumar, Neurologist at Apollo Hospitals in Hyderabad, said that plant-derived Vitamin D3—usually obtained from lichen, algae, or modern fermentation methods—provides an animal-free option without sacrificing effectiveness.

In a post on X, he noted that while plant-based Vitamin D3 is welcome news for vegans and those seeking cruelty-free supplements, both forms work equally well. He added that there is no medical need for people to switch if they are already taking conventional Vitamin D3 supplements.

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India has approved its first plant-based Vitamin D3 (cholecalciferol) ingredient, a move that could expand options for food fortification and dietary supplements while addressing the country's widespread Vitamin D deficiency.

The Food Safety and Standards Authority of India (FSSAI) has cleared VITADEE Green, developed by Fermenta Biotech, for use in health supplements, nutraceuticals and food products.

The company stated that the ingredient is produced using an India-patented process and offers a sustainable, scalable and vegetarian-friendly source of Vitamin D3.

The approval allows Indian manufacturers to incorporate the ingredient into fortified foods, beverages and dietary supplements.

It is particularly significant for vegetarians and vegans, who have traditionally had limited access to Vitamin D3 because most supplements are derived from lanolin, a by-product of sheep's wool.

The approval also supports India's broader efforts to improve nutrition through food fortification, an area where experts say Vitamin D remains a major gap.

What Is Vitamin D3?

Vitamin D3, often called the "sunshine vitamin," is produced by the body when the skin is exposed to sunlight.

It helps the body absorb calcium, maintain healthy bones and teeth, and lowers the risk of fractures. In children, severe deficiency can lead to rickets, while in adults it increases the risk of osteoporosis, muscle weakness, and falls.

Beyond bone health, Vitamin D3 also supports immune function. Research suggests low Vitamin D levels may be associated with increased susceptibility to infections and higher levels of inflammation.

Who Should Take Vitamin D3 Supplements?

The experts said the key question is whether supplementation is needed, not whether the source is plant- or animal-derived.

"The source matters mainly for ethical, dietary or personal preference—not for efficacy," Dr. Sudhir said.

Dr. Bagwala cautioned against taking high-dose Vitamin D without medical advice, as excessive intake can raise calcium levels and increase the risk of kidney stones and other complications.