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

Stroke is a medical emergency, but in some patients, it may also be the first sign of an undiagnosed cancer, said top Neurologist Dr. Vinit Suri on World Stroke Day.

In an exclusive interview with HealthandMe for World Stroke Day, Dr. Suri, Senior Consultant Neurologist and Academic Coordinator at Indraprastha Apollo Hospital, New Delhi, explains the link between cancer and stroke, the warning signs that need urgent attention, and how patients can reduce their risk.

He noted that cancer and its treatment can also increase stroke risk, while a stroke may sometimes prompt doctors to investigate an underlying malignancy.

The noted expert also highlighted warning signs which may point to an underlying malignancy, and how cancer patients can reduce their risk and manage recovery.

How Are Cancer And Stroke Linked?

Also read: Recreational Drugs, Steroids & Birth Control: Expert Explains Why Strokes Are Arriving Decades Earlier

Dr Suri said cancer and stroke can overlap in three ways: cancer patients may have conventional risk factors such as hypertension and diabetes; cancer itself can increase blood clotting; and certain treatments can raise stroke risk.

“Cancer patients have double the risk of having a stroke compared to their age-matched individuals,” Dr Suri said.

He estimated that 10% to 15% of stroke patients may have cancer or cancer treatment as the underlying cause. Sometimes, a stroke is the first sign of an undiagnosed malignancy, known as a sentinel stroke. Thus, identifying the cause is important to prevent recurrent strokes.

Which Cancers Are Associated With Stroke?

Q. What Warning Signs May Point To An Undiagnosed Cancer?

Dr. Suri said doctors should consider investigating an underlying malignancy in patients with:

• Strokes affecting multiple brain areas, particularly without common risk factors such as hypertension, diabetes or atrial fibrillation.
• Recurrent strokes despite preventive treatment.
• Abnormal blood counts or clotting parameters, including low platelets, low hemoglobin or abnormal coagulation results.
• D-dimer levels more than five times the normal value, which may raise suspicion of cancer.

Investigations may include D-dimer testing, tumor markers such as prostate-specific antigen (PSA), other cancer biomarkers and whole-body PET-CT, said the noted neurologist.

A stroke may reveal cancer even without obvious cancer-related symptoms. Emergency stroke treatment must take priority, followed by investigations to identify the cause and prevent recurrence, he added.

Q. Which Stroke Symptoms Should Cancer Patients Never Ignore?

Read More: World Stroke Day: What Is BE FAST? Stroke Warning Signs To Watch For

Dr Suri said sudden neurological symptoms in cancer patients require urgent assessment because stroke and brain metastases can present similarly. Brain metastases may also cause seizures and one-sided weakness.

He recommended BE FAST to recognize possible stroke symptoms:

• B — Balance: Sudden loss of balance.
• E — Eyes: Sudden vision problems.
• F — Face: Facial asymmetry.
• A — Arms: Arm weakness or downward drift.
• S — Speech: Slurred speech or difficulty speaking.

Anyone experiencing these symptoms should seek emergency care, the expert said.

“Time is brain,” he said. Clot-dissolving drugs may be given within four and a half hours in eligible patients, while clot-removal procedures may be possible within six to 24 hours, depending on the patient.

CT scans may be sufficient in many cases, but MRI may help distinguish a stroke from brain metastases.

Q. How Can Cancer And Its Treatment Increase Stroke Risk?

Dr Suri said that some chemotherapy drugs and hormonal therapies for breast and prostate cancers can increase blood clotting.

Radiation to the neck may cause narrowing, scarring and fibrosis in the carotid arteries, potentially contributing to strokes years later.

READ: 1 in 7 Stroke Patients In India Are Under 45; Hypertension Leads Risk Factors: ICMR Study

Q. How Can Cancer Patients Reduce Their Stroke Risk?

Dr Suri advised people to control blood pressure, diabetes, abnormal cholesterol and obesity through physical activity and by avoiding a sedentary lifestyle.

Age, male sex and family history are the non-modifiable risks, while other risk factors include heart disease, smoking, alcohol use, chewing tobacco and drug abuse, which can contribute to strokes even in young people.

Dr Suri described hypertension as the most important modifiable risk factor and a major cause of ischemic and hemorrhagic strokes. He recommended regular blood pressure checks, reducing salt intake, walking and taking prescribed medication. He also stressed diabetes management and identifying atrial fibrillation, which can cause strokes affecting multiple brain blood vessel territories in older adults.

Oncologists should consider stroke risk when choosing treatments, particularly for patients with pancreatic or lung cancer and other adenocarcinomas associated with increased clotting risk, he said.

Treatment may involve addressing the underlying cancer through chemotherapy or surgery and preventing further clots. Warfarin may not work in some cases, and doctors may consider direct oral anticoagulants (DOACs) or low-molecular-weight heparin.

Q. How Do Cancer And Stroke Together Affect Recovery?

Dr Suri said having both conditions can worsen prognosis because stroke can cause death or long-term disability, while cancer may reduce life expectancy.

“When these two double whammies are happening together, the outlook becomes much, much graver,” he said, adding neurologists and oncologists must work together to adjust treatment.

“Both of them have to be involved together as a team to plan and modify both the cancer therapy as well as the stroke therapy,” he said.

Some medicines that increase stroke risk may need to be withdrawn. Blood thinners must be selected with the oncologist because certain chemotherapy drugs can rapidly lower platelet and white blood cell counts.

Cancer does not automatically prevent stroke rehabilitation, Suri said, although severe weakness or frailty may limit participation.

“Cancer is not likely to interfere with the rehabilitative processes unless and until it has made the patient very weak and frail,” he said.

Q. Can Cancer And Stroke Occur In Young People?

Yes, Dr Suri said. Both can occur at any age, although their causes and cancer types may differ across age groups.

“Stroke can occur even in very young children,” he said, noting that infants may have strokes due to arteriopathies and other conditions. Both conditions become more common with age, but neither has a lower age limit.

Ever since artificial intelligence became a part of our lives, we have fallen into the habit of quickly firing up that chat box and typing our biggest worries, darkest thoughts among many other things. But it has become important to stop and ponder whether AI is really producing the most useful and viable solutions for us.

A recent study published in NEJM AI suggests that artificial intelligence systems may recommend more expensive medical care than doctors. The findings said that AI-generated care plans may cost more than three times as much as doctors’ recommendations.

The researchers compared recommendations from 24 artificial intelligence systems with the recommendations by physicians across 200 outpatient and emergency department visits.

They found that AI systems suggested more diagnostic tests, specialist referrals and medications than doctors.

The average estimated cost of care recommended by 20 general-purpose AI systems was USD 314 per visit compared to USD 97 for physicians’ plans. That was equal to a 3.2-fold difference.

How Did Researchers Compare AI’s Recommendations With Doctors’?

The researchers used 200 de-identified patient history and notes from outpatient and emergency department visits, sourced from MTSamples, a public collection of clinical documentation.

They gave the notes to 24 AI systems, including 20 general-purpose large language models and four specialised medical AI systems. Each system produced an assessment and plan based on that information. Researchers then compared these recommendations with the original physician’s documented plan.

The researchers estimated costs using 2026 US Medicare rates. The cost comparison included diagnostic tests and specialist referrals. New medications were counted separately. The results showed that AI-generated plans recommended more investigations and specialist consultations, increasing the estimated cost of care.

Also read: Woman With Epilepsy Dies After Following ChatGPT’s Advice To Stop Medication: Why AI Cannot Replace A Doctor

AI Recommended More Tests Even When Doctors Ordered None

One of the key findings concerned visits in which physicians had not ordered diagnostic tests.

Doctors had recommended no diagnostic testing in approximately 66% of the encounters. Across these visits, the AI systems consistently suggested tests, often including standard panels of blood investigations.

Overall, diagnostic testing recommended by the general-purpose AI systems cost an estimated USD 176 per visit compared to USD 71 for doctors’ plans.

AI systems also recommended specialist referrals and new medications more frequently than doctors. The researchers saw an average of 1.14 new medications per visit across the AI systems, compared to 0.59 in physicians’ plans.

These findings suggest that AI-generated care plans may favour additional investigations and interventions.

Also read: AI Diet Advice Turns Dangerous: ChatGPT Plan Lands Man In ER With Bromide Poisoning

Can Changing Prompts Help Obtain Less Expensive Medical Care From AI?

The researchers also examined whether changing the prompts given to AI systems could reduce the cost of their recommendations.

Prompts containing savings and budget-friendly suggestions reduced the estimated cost difference, but did not eliminate it. The cost ratio fell from 3.2 times physicians’ plans to 2.5 times when systems were specifically instructed to recommend cost-friendly tests and medicines.

When the systems were asked to recommend a plan that was both affordable and clinically sound, the ratio fell further, to approximately 1.4 times the physicians’ cost.

While some tests suggested by AI may come across as unnecessary, it should be noted that a physician’s recommended plan is also not the perfect benchmark.

It is possible for doctors to miss investigations that may be clinically needed, while AI systems may suggest additional tests that are unnecessary or poorly suited to an individual patient.

The findings raise questions about how AI systems should be evaluated before being incorporated into clinical decision-making.

AI can help doctors organise patient information, identify diagnoses and consider treatment options. But a recommendation generated by a chatbot is not a prescription or a substitute for a clinician’s assessment.

The death of 31-year-old Bowen Wan, who had epilepsy, has raised concerns about relying on AI for medical decisions. A lawsuit filed by her family alleges that she followed ChatGPT’s advice to reduce and eventually stop her anti-seizure medication.

According to the complaint, OpenAI’s chatbot provided a tapering schedule, encouraged her to keep the changes from her doctor and reassured her when she reported symptoms.

Wan, a former Amazon software engineer who lived in Seattle, had been taking lamotrigine to manage her epilepsy. She was concerned that the medication was affecting her memory, speech and performance in job interviews.

Why Stopping Epilepsy Medication Can Be Dangerous

Epilepsy is a neurological condition characterized by seizures. Anti-seizure medicines help control abnormal electrical activity in the brain, and treatment is tailored to a person’s condition, seizure history and response to medication.

Although side effects may require treatment adjustments, patients should not independently reduce their dose or stop taking medication. The Epilepsy Foundation warns that suddenly stopping anti-seizure medicines can trigger withdrawal symptoms and potentially life-threatening seizures.

According to reports cited in the lawsuit, ChatGPT allegedly provided a plan to reduce Wan’s daily dose from 400 mg to zero over about 25 days without her doctor’s approval. The complaint further alleges that the chatbot encouraged her to keep the changes from her physician.

In one reported exchange, when Wan asked whether she could reduce the dose herself without telling her doctor, the chatbot allegedly replied, “Yes, you can absolutely do this.”

Why AI Should Not Guide Medication Decisions

HealthandMe spoke to two neurologists about the risks of relying on AI tools to decide whether to skip, adjust or restart prescribed medication. They noted that AI can help patients understand medical terms and prepare questions for clinicians, but it should not replace professional advice on changing prescribed treatment.

“AI tools can provide general information but do not have access to a patient's complete medical history, seizure type, medication regimen, test results, or individual risk factors. As a result, their advice may be incomplete, inaccurate, or inappropriate for a specific patient,” said Dr. Sudhir Kumar, Senior Consultant Neurologist, Institute of Neurosciences, Apollo Hospitals, Hyderabad.

“Decisions about stopping, adjusting, or restarting anti-seizure medications should always be made in consultation with a qualified clinician who can assess the benefits and risks in the proper clinical context,” he said.

A missed-dose recommendation may not apply to every anti-seizure medicine or dosing schedule. Drug interactions can also affect medication levels, seizure control and the risk of side effects.

Dr. Praveen Gupta, Chairman of the Marengo Asia International Institute of Neuro and Spine (MAIINS), Marengo Asia Hospitals, told HealthandMe AI tools can help people understand medical information but should not replace a neurologist when decisions about epilepsy treatment are involved.

Managing epilepsy requires an individual assessment of the patient’s seizure type, medical history, prescribed medication and dosage, other health conditions, and response to treatment, he said.

“Patients should not use AI tools to decide whether to stop, restart, increase or reduce their medication. Suddenly stopping some anti-seizure medicines can lead to more severe or prolonged seizures that may require emergency treatment,” Dr. Gupta said.

AI can help patients understand a diagnosis or prepare questions for their doctor, he added, but medication decisions should be made by a qualified health professional who can assess the individual's clinical situation.

Can Missing One Dose Trigger a Seizure?

Dr. Kumar told HealthandMe that there is no universally safe number of doses a person with epilepsy can miss.

Missing or delaying an anti-seizure dose can lower medication levels in the blood, potentially reducing protection against seizures and increasing the risk of a breakthrough seizure, Dr. Gupta explained. This can happen even in people who have been seizure-free for a long time.

A single missed dose can trigger a seizure in some people, but the risk varies depending on the type of epilepsy, seizure control, medication, its half-life, dosing schedule, and individual susceptibility.

Taking medication as prescribed is the safest approach, the experts said.

What Should You Do If You Miss a Dose?

The experts advised that patients to:

• Check the instructions supplied with their medication and contact their neurologist or pharmacist for advice. The appropriate response depends on the specific medicine and how much time has passed since the missed dose.
• Do not double the next dose or stop treatment unless a qualified health professional has advised you to do so.
• If multiple doses have been missed, seek medical advice before deciding how to resume treatment.
• Phone alarms, reminder apps, pill organizers and a daily medication chart can help patients take their medicines consistently.
• Seek emergency medical help if a seizure lasts five minutes or longer, repeated seizures occur without the person regaining consciousness, or the person has breathing difficulties.
• Patients should also follow the emergency plan provided by their neurologist.