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

You can feel fine and still have a heart that is slowly changing. Researchers at Imperial College London and the MRC Laboratory of Medical Sciences say millions of people could be living with hidden inflammation that does exactly that. They say the changes can start years before any symptoms show up.

"Our study, which is the largest of its kind, suggests that millions of people could be living with hidden inflammation, which is slowly changing their heart and causing long-term damage," said Professor Declan O'Regan, British Heart Foundation Chair of Cardiovascular AI at Imperial College London.

What The Study Found

The study was published in the European Journal of Preventive Cardiology. The team looked at data from nearly 480,000 adults in the UK Biobank, a large health database, Imperial says. They measured a blood marker called glycoprotein acetyls, or GlycA for short, which the paper uses to measure chronic inflammation. They also used heart scans and genetic data.

People with the highest levels of inflammation, the top 20%, had a 43% higher risk of heart attack and stroke than those with the lowest levels, the bottom 20%, according to Imperial.

Imperial adds that higher levels also went with changes in the heart itself. These included thicker heart walls, smaller heart chambers and poorer filling of the heart. The researchers say such changes can build quietly for years before possibly leading to heart failure.

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Where The Inflammation Comes From

Chronic inflammation is a long-term, low-level activation of the immune system, Imperial explains. It has been linked to cancer and diabetes, and is increasingly seen as a driver of heart disease.

According to Imperial, higher inflammation was strongly linked to poorer social and economic circumstances and to mental distress, as well as to smoking and excess body fat.

"The surprising thing was how much social factors and mental health are linked to inflammation and damage to the heart, as well as more well-known risk factors like smoking and inactivity," O'Regan said. He added that there was also a strong genetic factor, "with some people being naturally more resilient or susceptible to the inflammatory damage that comes from different lifestyles."

What Could Come Next

The study named proteins from the interleukin-1 and TNF families as likely drivers of the damage, Imperial says. Several are already targeted by drugs in clinical trials, which Imperial says raises hopes that anti-inflammatory treatments could help prevent heart disease before symptoms begin. The researchers say combining inflammation blood tests with genetic risk scores could help find the people who would benefit most from early action.

There is earlier proof that this idea can work. In the 2017 Canakinumab Anti-inflammatory Thrombosis Outcomes Study, or CANTOS trial for short, led by Paul Ridker and published in the New England Journal of Medicine, 10,061 people who had already had a heart attack, and had high inflammation, were given canakinumab or a placebo. The paper concluded that at the 150 mg dose, given every three months, canakinumab led to fewer repeat cardiovascular events than the placebo, independent of any drop in cholesterol. But those were heart attack survivors, not people without symptoms.

What to keep in mind

The study reports links, and the researchers describe inflammation as one possible pathway to heart damage. They also stress that being genetically susceptible, or living in hard circumstances, does not mean a person will develop heart disease, and that much can be done to prevent long-term inflammation.

A few floaters, a brief flash of light or mild blurring across your vision may seem harmless at first. But when these changes appear suddenly without any probable cause, they may signal a bigger problem. On World Retina Day, experts explain when your retina needs urgent medical attention.

The retina is the light-sensitive layer at the back of the eye, which plays a crucial role in maintaining healthy eyesight. Some retinal conditions may develop without obvious symptoms in early stages, while others can present suddenly and threaten your eyesight if treatment is delayed.

“Retinal health is fundamental to maintaining clear vision and preserving quality of life, yet many retinal conditions can develop silently, without obvious warning signs in their early stages,” Dr Rajesh Kapoor, Medical Director, Suruchi Eye Hospital, Navi Mumbai told HealthandMe.

“By the time a person begins to notice blurred or distorted vision, dark spots, flashes, floaters, or other visual changes, the condition may already require urgent medical attention. This is why we need to shift our approach from waiting for symptoms to prioritizing awareness, regular comprehensive eye examinations and timely consultation with an ophthalmologist.”

What Are Floaters And Flashes?

Floaters can look like tiny dots, lines, specks or cobweb-like shapes moving across your field of vision. They are easier to notice when looking at a bright background.

Flashes, on the other hand, can look like brief streaks or bursts of light. They may occur even when there is no actual source of light around you.

Occasional floaters can occur for reasons that are not always serious. However, a sudden increase in floaters or the sudden appearance of flashes should not be dismissed, especially if there are other changes in vision. One of the conditions doctors want to rule out in such situations is retinal detachment.

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What Is Retinal Detachment?

“Retinal detachment is a serious condition which requires urgent medical attention and occurs when the retina, the light sensitive layer at the back of the eye pulls away from its normal position,” Dr Mudit Tyagi, Scientific Chair, VRSI and Head, Smt Kanuri Santhamma Center for VitreoRetinal Diseases, L V Prasad Eye Institute, Hyderabad told HealthandMe.

There are several possible causes of retinal detachment. According to Dr. Tyagi, they include injury to the eye, high myopia and certain eye diseases.

When the retina separates from its normal position, its ability to function properly can be affected. The longer the condition remains untreated, the greater the concern about permanent vision loss.

Sudden Flashes And A Curtain Or Shadow Over Your Vision

The symptoms of retinal detachment can vary, but certain changes should warrant immediate medical attention.

A dark curtain or shadow across the field of vision is concerning because it can represent a portion of the visual field being lost.

Dr. Tyagi said, “The urgency of recognising retinal detachment can’t be overstated. If you have sudden flashes of light, a dramatic increase in floaters, or a dark shadow or curtain across your field of vision, don’t ignore it, even if there is no pain.”

The absence of pain should not be misconstrued as a non-emergency. A retinal problem can occur without the kind of discomfort people usually associate with an eye emergency.

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Timing Is Key

Retinal detachment is not a condition where it is advisable to wait and see whether symptoms settle on their own. “Retinal detachments, if detected in time and operated early enough can result in a good recovery of vision,” Dr Tyagi said.

He added, “It is important, therefore, to be vigilant and see an eye care specialist as early treatment can help avoid preventable loss of vision. So, timely recognition and diagnosis followed by right treatment can help save vision.”

This is why sudden visual changes deserve attention even if they seem minor initially.

Who Is At Risk?

Some people may need to be particularly proactive about retinal health. Dr. Kapoor said individuals with diabetes, increasing age, a family history of retinal disease or other risk factors that may affect retinal health should be more careful and alert.

Diabetes can affect the blood vessels supplying the retina and lead to diabetic retinal disease. Regular eye examinations can help identify changes before vision is significantly affected. Dr Kapoor also stressed that screening should not necessarily wait until symptoms appear.

“Advances in retinal imaging, diagnostics and treatment today provide ophthalmologists with valuable opportunities to identify and manage several retinal conditions at an earlier stage. However, technology can make its greatest impact when people seek eye care at the right time.”

A sudden change in vision does not automatically mean that a person has retinal detachment. But because some retinal conditions can progress rapidly, it is important to have sudden symptoms assessed rather than trying to determine their cause on your own.

Dr Kapoor said: “Through greater public awareness and proactive screening, we can encourage people to take retinal health more seriously. Protecting sight begins with understanding that healthy vision should never be taken for granted—because when it comes to the retina, we should not wait for a problem to become noticeable before taking action.”

After surgery, radiotherapy could significantly decrease the chances of an atypical meningioma returning, according to a new international phase 3 trial published in The Lancet.

The findings come from the ROAM/EORTC-1308 trial, the first randomised controlled trial to directly test whether patients with a completely removed atypical meningioma benefit from receiving radiotherapy or whether regular scans and observation are enough.

The results could help settle a treatment question that has remained uncertain for years.

What Is An Atypical Meningioma?

Meningiomas are the most common brain tumours in adults. They develop from the meninges, the protective membranes surrounding the brain, and spinal cord.

An atypical meningioma is classified as a WHO grade 2 tumour. Unlike grade 1 meningiomas, that generally grow slowly, grade 2 tumours are more likely to grow again after surgery.

Even when surgeons manage to remove the entire visible tumour, microscopic tumour cells may remain, sparking a risk of recurrence.

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What Did The Lancet Study Find?

The ROAM/EORTC-1308 trial enrolled 157 patients whose atypical meningiomas had been completely removed surgically. They were randomly assigned to either:

• Radiotherapy: 78 patients received 30 sessions of radiotherapy
• Observation: 79 patients underwent regular imaging surveillance

After a median follow-up of about five years, the difference in recurrence was significant. 14% of patients in the radiotherapy group experienced a recurrence, compared to 30% in the observation group. In other words, the risk of recurrence was reduced by nearly half with postoperative radiotherapy.

Additionally, at five years, about 80% of patients receiving radiotherapy remained free of recurrence, compared to about 64% of those who were monitored without immediate radiotherapy.

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The Trial Cements Necessary Evidence

Until now, doctors have had to weigh two approaches after complete surgical removal of an atypical meningioma.

One option is to give radiotherapy immediately, hoping to destroy microscopic tumour cells that surgery may have missed. The other is to monitor the patient with regular brain scans and use radiotherapy if the tumour returns.

The uncertainty existed as strong randomised evidence showing whether immediate radiotherapy actually reduced recurrence had been lacking. The trial helps cement that evidence.

Who Needs Radiotherapy After Surgery?

The researchers say that treatment decisions still need to be made jointly by doctors and patients, taking into account possible side effects and the long-term consequences of radiation treatment. Serious radiation-related complications were uncommon in the trial.

The study also did not establish whether the recurrence benefit extends beyond five years. This means that longer follow-up will be needed to gather more evidence. According to the researchers, the findings are expected to shape national and international treatment guidelines.

The options may extend for patients who have undergone complete removal of a WHO grade 2 atypical meningioma. Rather than contemplating “Should we simply watch and wait?”, they can consider moving to a more evidence-based discussion about whether postoperative radiotherapy should be offered upfront.