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

Actress Jenny McCarthy has opened up about the lasting effects of her battle with mold poisoning, revealing that the experience has left her with post-traumatic stress disorder (PTSD), anxiety and a fear of being exposed to mold again.

During a recent episode of her podcast, The Jenny McCarthy-Wahlberg Show, the actress spoke about the physical and emotional toll of the illness, the extensive measures she has taken to avoid further exposure and her ongoing recovery.

McCarthy said she had to discard most of her belongings after the suspected exposure, including her clothes and furniture.

"I wound up throwing everything away," she said, adding that she and her husband, Donnie Wahlberg, also left their furniture behind when they moved out of their Los Angeles home.

Although she believes the exposure may have originated in her makeup room, she said she did not want to take any chances.

Jenny McCarthy Says Mold Poisoning Left Her With PTSD

Also read: One In Three Hospital Patients With Serious Mould Infections Died, CDC Study Finds

McCarthy said the experience made her fearful of encountering mold wherever she went. She described having histamine reactions in different places and struggling with everyday activities, including travelling in Ubers, visiting restaurants and boarding airplanes.

The actress also revealed that the prolonged health struggles contributed to a nervous breakdown, leaving her husband worried about her well-being.

Having undergone 11 surgeries in 15 months, McCarthy said she became increasingly afraid that her body would start "falling apart again."

She also described the emotional strain of her treatment, which involved taking around 100 pills a day.

"I find myself crying sometimes," she said, describing how difficult it was to manage the medication and the uncertainty surrounding her recovery.

Jenny McCarthy's Symptoms And Mycotoxin Poisoning Diagnosis

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McCarthy first spoke publicly about her health ordeal in March, describing six months of what she called "living hell."

She previously reported experiencing an infected root canal, pus-filled growths on her eyelids, mouth infections, tooth pain, skin rashes and food allergies.

The actress said a doctor diagnosed her with mycotoxin poisoning in December 2025. She has since described being in remission for seven months and focusing on recovery.

Her efforts to avoid further exposure have also been extensive. In an October 29 podcast episode, she revealed that she had been sleeping in a tent in her backyard because she was afraid of being exposed to mold indoors.

"Because I am paranoid now about basically sleeping anywhere, I live in a tent," she said.

McCarthy has also spoken about concerns over her breast implants and whether they could be associated with mold exposure. During a November 3 podcast episode, she discussed the issue with plastic surgeon Dr Terry Dubrow, who has treated her previously.

What Is Mycotoxin Poisoning And How Can It Affect Health?

Mycotoxins are toxic substances produced by certain molds and other fungi. Exposure can occur through contaminated food or environments, depending on the type of toxin and the route of exposure.

According to the Cleveland Clinic, mycotoxin exposure can affect different parts of the body, including the digestive system, eyes and mouth. Mold exposure can also trigger allergic reactions and worsen respiratory conditions such as asthma.

The health effects depend on factors such as the type of mycotoxin, the amount and duration of exposure, and an individual's susceptibility.

In a bizarre medical case, a 28-year-old US man began seeing his pet cat Luna’s features on human faces after brain surgery. These included almond-shaped eye sockets enlarged pupils and stripes.

If Karl sees Luna first thing in the morning, he continues to see her features on human faces throughout the day, whether in person or online.

However, if he wakes up looking at a human face, he may see that person’s pupils and eye shape on other people’s faces and even on his cat.

According to a case report published in the journal Cortex, Karl experiences a form of palinopsia, in which something seen earlier persists or reappears in subsequent perception. In his case, this causes facial distortions known as prosopometamorphopsia (PMO).

How Did The Condition Begin?

Also read: Rare Canine Tooth Found In Indian Teen’s Eyelid: What Is An Ectopic Tooth?

Karl, who lives in the northeastern US, has experienced the condition for two years. It began after surgery to remove part of his right temporal lobe to treat an arteriovenous malformation (AVM), an abnormal tangle of blood vessels connecting arteries and veins that can cause bleeding in the brain.

The right temporal lobe plays an important role in face processing.

"This case of Karl seeing his cat's features in human faces and vice versa demonstrates that individual features can be pulled from memory and influence our ongoing perception," said lead author Brad Duchaine, professor and chair of psychological and brain sciences and principal investigator of the Social Perception Lab at Dartmouth.

More Than 250 People Experience Facial Distortions

Karl is not alone. According to Duchaine's lab, more than 250 people experience facial distortions. Many are mistakenly diagnosed with psychiatric problems.

"We have heard from people who have been told that they had a psychiatric problem and, in some cases, have even been put on antipsychotics, when they are in fact just having visual problems," Duchaine said.

Duchaine also cited a 1986 study published in Cortex. It described a woman who saw a poodle sitting on a passenger's lap while riding a bus. She then began seeing the poodle's face on every passenger. The woman had experienced a stroke nine months earlier.

Unlike that case, Karl sees individual facial features transferred between faces rather than entire faces.

How AI Can Help

Also read: Hours Of Sitting, Gaming And Binge-Watching OTT? Doctors Warn Of Blood Clot Risk In Young People

Duchaine used a large language model to turn a line drawing of Karl’s experience into a photorealistic image. He then worked with Karl to refine the visuals featured in the report.

AI-generated images can help researchers understand visual distortions and help patients explain their experiences to doctors, friends and family, Duchaine said, adding that he will continue working with Karl to decode more about the condition.

What Is Prosopometamorphopsia?

Prosopometamorphopsia (PMO) is a rare visual condition in which faces or facial features appear distorted due to changes in the brain's face-processing network. The term combines prosopo (Greek for face) and metamorphopsia (perceptual distortion).

People with PMO may see facial features as:

• Droopy or stretched

• Larger or smaller than normal

• Displaced or out of position

• Distorted in specific parts of the face

Two prominent subtypes are:

• Full-face PMO: The entire face appears distorted

• Hemi-PMO: One half of the face appears distorted

Most cases last days or weeks, although some persist for years. Around 75 case reports have so far been published.

Rubbing your eyes is a common habit, often triggered by itching, dryness or tiredness. However, frequent and vigorous rubbing can damage the cornea and increase the risk of keratoconus, a progressive condition that causes it to thin and bulge outward, experts warn.

World Keratoconus Day is observed every year on November 10 to raise awareness about the condition.

Early diagnosis is important to slow its progression. Frequent changes in spectacle prescriptions or deteriorating vision should prompt an eye examination.

Why Should You Avoid Rubbing Your Eyes?

Frequent or aggressive eye rubbing can put mechanical stress on the cornea, potentially weakening its structure and worsening existing eye conditions.

Speaking to HealthandMe, Dr Janhvi Mehta, Consultant Ophthalmologist, Jaslok Hospital and Research Centre, Mumbai, said, "Frequent or vigorous eye rubbing can damage the cornea, particularly by contributing to keratoconus. It can also cause corneal epithelial injury and worsen existing ocular allergy."

Repeated rubbing can:

• Contribute to corneal thinning and biomechanical weakening.
• Accelerate keratoconus in susceptible individuals.
• Cause corneal abrasions and increase the risk of infection.

Also read: Ozempic, Zepbound: US FDA Orders New Warning Over Rare Eye Risk

Dr Mahipal Singh Sachdev, Chairman and Managing Director, Centre for Sight Group of Hospitals, explained that excessive rubbing puts pressure on the cornea and can damage its collagen structure.

"The cornea might become thinner than usual or its shape may become uneven, leading to impaired vision. Hence, people should avoid the habit of rubbing their eyes," he told HealthandMe.

Why Are Children More At Risk?

Children with allergies, especially allergic conjunctivitis, may be more vulnerable to keratoconus because of frequent eye rubbing.

Allergies can cause persistent itching, redness, watering, and discomfort, encouraging children to rub their eyes repeatedly. The resulting mechanical stress may contribute to the development or progression of keratoconus in susceptible individuals.

The experts urged parents to watch for excessive rubbing and changes in their children's vision. Timely allergy treatment and regular eye examinations can help identify potential problems early.

Other risk factors for keratoconus include:

• Vernal keratoconjunctivitis (VKC)
• Atopic eye disease
• Family history of keratoconus
• Genetic predisposition
• Certain connective tissue disorders

However, not everyone who frequently rubs their eyes develops keratoconus.

Read More: 6 Million People In Delhi Living With Poor Vision: AIIMS Study

Why Is Keratoconus Often Diagnosed Late?

Dr Janhvi noted that keratoconus commonly begins during adolescence or early adulthood but may remain undiagnosed until vision deteriorates.

Its early symptoms can resemble common refractive errors such as myopia. Children and young adults may experience mild blurring or require frequent changes in their spectacle prescriptions, which can be mistaken for routine vision changes.

The condition can also progress gradually and initially affect only one eye, making changes harder to recognise. Routine eye examinations may not always detect early keratoconus without specialised corneal assessment, Dr. Mahipal said.

Warning signs to watch for include:

• Increasing myopia
• Progressive or irregular astigmatism
• Frequent changes in spectacle prescriptions
• Reduced visual clarity despite corrective lenses
• Ghosting, glare or double vision in one eye
• Difficulty driving at night

Increasing astigmatism despite repeated spectacle corrections is an important warning sign that warrants further evaluation.

Read More: Sudden Floaters, Flashes Or Blurred Vision? When Should You Seek Emergency Care For Retinal Changes

How Can You Prevent Corneal Damage?

Preventing excessive eye rubbing and managing its underlying causes can help reduce avoidable stress on the cornea.

1. Break the eye-rubbing habit

• Avoid pressing or massaging closed eyelids.
• Use a cold compress when your eyes itch.
• Avoid rubbing your eyes even through a towel or handkerchief.
• Keep children's fingernails short to minimise accidental injury.

2. Treat underlying allergies

If itching triggers eye rubbing, consult an ophthalmologist about appropriate treatment. Options may include topical antihistamine or mast-cell stabiliser drops, such as olopatadine or ketotifen.

Other measures include:

• Using preservative-free artificial tears for irritation
• Treating associated blepharitis or dry eye
• Avoiding prolonged use of topical steroid drops without medical supervision

3. Reduce exposure to environmental triggers

• Avoid dust, smoke and known allergens
• Wear protective glasses outdoors
• Avoid direct airflow from air conditioners.