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

Changes in stride like a slower walking pace, fewer steps or a change in the way your arms move may be considered as signs of ageing. However, an emerging study suggests that minor differences in walking patterns could be subtle, early indicators of Parkinson’s disease. According to the study, these signs can can emerge years before Parkinson's diagnosis.

Published in the Journal of Neural Transmission, the study analysed movement data from more than 73,000 participants in the UK Biobank. Researchers found that certain changes in walking behaviour could indicate a future Parkinson’s diagnosis, surfacing up to 6.8 years beforehand.

The findings indicate that Parkinson’s disease may begin developing long before its more familiar symptoms like tremors and stiffness, become noticeable.

Findings From The Study

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Researchers examined data from 73,413 people who wore wearables that track movement for seven days. Their health records were then followed for up to 10 years. Of the participants without Parkinson’s at the time of the movement assessment, 314 were diagnosed with the disease during follow-up.

Using a digital analysis tool called Watch Walk, researchers examined 17 characteristics related to gait. They identified five walking characteristics that were consistently linked with a subsequent Parkinson’s diagnosis:

• Fewer steps each day: Participants who later developed Parkinson’s recorded lower daily step counts than those who did not.
• Slower walking speed: People who were diagnosed later tended to walk more slowly, including at their maximum walking speed.
• Shorter walking periods: They also spent a lesser amount of their time walking in longer, continuous stretches.
• Changes in step regularity: Their steps showed less consistent rhythm, indicating alterations in the regularity of their walking pattern.
• Reduced natural arm swing: They spent more time walking with their arms in a static position instead of swinging naturally.

Effects Of Parkinson’s Disease On Walking

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Parkinson’s disease is a progressive neurological disorder that affects movement. It occurs due to the loss of nerve cells that produce dopamine in a brain region called the substantia nigra. Dopamine helps regulate movement, coordination and other functions.

As dopamine levels decline, the brain's ability to coordinate movement is affected. This can lead to bradykinesia, or slowness of movement, rigidity of muscle, tremors and balance issues.

These changes can also affect gait. A person may take smaller steps, walk more slowly, experience difficulty moving or reduced swinging arms.

The study's findings suggest that some of these motor changes may be detectable in everyday movement well before the condition is formally diagnosed.

Changes in walking speed, balance, step length or arm movement can occur for several reasons, including ageing, joint problems, injuries, medication effects and other neurological conditions.

Parkinson’s disease is, however, diagnosed through a clinical assessment, which considers a person's symptoms, medical history and neurological examination. Other symptoms that may warrant medical evaluation include:

• A tremor especially when the affected hand or limb is at rest.
• Slowness in everyday movements like dressing or getting up from a chair.
• Muscle stiffness or rigidity.
• Problems with balance.
• Smaller handwriting or changes in speech volume.

Early Detection Of Parkinson’s Disease

Although there is currently no established treatment that stops or reverses the underlying progression of Parkinson’s disease, an earlier diagnosis can help people manage symptoms, access rehabilitation and support sooner.

Exercise, physiotherapy and medical care can help maintain mobility, balance and quality of life. Early assessment can also help doctors distinguish Parkinson’s from other conditions that may cause similar movement difficulties.

After the social media trend of ‘ferritin face’ had everyone scrutinising their face for pale skin, dark circles and sluggish features due to low iron levels, attention is now shifting to hair. Described as ‘ferritin hair’, social media users have been attributing symptoms like unusual hair shedding, thinning and brittle strands to the body’s low iron stores.

The trend is not just a fluke. There is a medical basis for recognising iron deficiency in people facing hair loss. However, ‘ferritin hair’ is not a formal medical diagnosis. Hair loss can be due to several reasons, including hormonal changes, stress, thyroid disorders, nutritional deficiencies and genetic hair-loss conditions.

So is there a connection between ferritin and hair health and which signs should prompt someone to seek medical advice?

What Is Ferritin And How Is It Connected To Your Hair?

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Ferritin is a protein that stores iron in the body and releases it when needed. A blood ferritin test helps assess the body's iron reserves. Iron is essential for several functions, including the production of haemoglobin, which carries oxygen in the blood.

When iron stores are exhausted, the body prioritises essential functions over those that are not absolutely necessary for survival. Hair growth may be affected in some people, contributing to increased shedding.

A 2023 clinical review published in Cutis noted that measuring serum ferritin can be useful while evaluating people with diffuse hair loss, especially to identify underlying iron deficiency.

A 2026 study published in Cureus reported that low serum ferritin and telogen effluvium in women may be connected.

A separate systematic review published in 2026 also found lower ferritin levels among people with telogen effluvium.

The European Food Safety Authority has also observed a cause-and-effect relationship between iron intake and the maintenance of normal hair growth.

Possible Signs Of 'Ferritin Hair'

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Hair shedding: One possible sign is diffuse hair shedding, in which more hair than usual falls from across the scalp rather than from one specific area. This can occur due to a condition called telogen effluvium, in which more hair follicles than usual enter the resting phase of the hair-growth cycle.

Hair thinning: Constant shedding can make the hair appear less dense over time. Some people may notice a wider-looking parting or thinner volume.

Dry or brittle hair: Iron deficiency may cause dry, brittle hair. However, hair texture can also be affected by heat styling, chemical treatments and other nutritional factors.

Other symptoms: Hair shedding may occur with other signs of iron deficiency like fatigue, weakness, poor concentration, breathlessness, palpitations or pale skin.

Causes Of Iron Deficiency Or Low Ferritin Levels

Iron deficiency can develop when the body loses more iron than it absorbs and does not receive enough through diet. Heavy menstrual bleeding and pregnancy are common reasons for iron deficiency. Other possible causes include:

• Inadequate dietary iron: People who do not consume enough iron-rich foods are at risk if their diets are restrictive.
• Poor absorption: Conditions such as coeliac disease can interfere with the absorption of iron.
• Blood loss: Gastrointestinal conditions like gastritis and intestinal polyps can sometimes lead to iron loss.
• Increased requirements: Pregnancy can demand increased iron needs.

Delhi’s air pollution has worsened even before the onset of peak winter. This has raised concerns about development and health of children who are constantly exposed to high levels of fine particulate matter (PM2.5).

While the immediate effects of polluted air like coughing, wheezing and breathing difficulties are known, research says that long-term exposure can also impact children’s developing brains, including effects on their memory, attention, IQ and ability to learn.

Delhi Winter Pollution Highest In 3 Years

On November 12, Delhi's air quality got listed under 'very poor' category. Stations like IIT Delhi and Delhi IITM recorded an AQI of 416, while NSUT Jaffarpur and Delhi DPCC recorded 404. Anand Vihar station recorded 319 while DTU Delhi stated 372.

A new analysis by the Centre for Science and Environment (CSE), released recently, found that Delhi’s average PM2.5 concentration during the week preceding Diwali stood at 236 micrograms per cubic metre (µg/m³), the highest in the last three years. This was 97% higher than the 120 µg/m³ recorded in 2025 and 32% above the 179 µg/m³ recorded in 2024.

The analysis also found that pollution levels during the early winter period were higher this year than in 2025. Vehicular emissions and pollution from neighbouring NCR districts were among the major contributors. The findings suggest that firecracker smoke from Diwali aggravated an already high pollution burden.

Delhi’s pollution crisis is not only threatening people’s lungs and cardiovascular health, it is also posing significant risks to children’s brain health. Could breathing polluted air affect how well children concentrate, recall information and learn at school?

Also read: World Pneumonia Day 2026: Post-Diwali Cough Or Pneumonia? Doctors Explain Warning Signs

Effects Of PM2.5 On Children’s Cognitive Health

PM2.5 refers to fine particulate matter with a diameter of 2.5 micrometres or smaller. These particles are small enough to travel deep into the respiratory system, fueling inflammation and oxidative stress. Not just lungs, their effects may reach children’s nervous systems.

Dr Sushil Singla, Director, Paediatrics, Sarvodaya Hospital, Sector 8, Faridabad told HealthandMe, “Exposure to PM2.5 (fine particulate matter) can affect children's cognitive development, including memory, attention span and learning abilities. These tiny particles can penetrate deep into the lungs and may trigger inflammation and oxidative stress, which can have wider effects on the developing brain. Children are particularly vulnerable because their brains are still developing and they inhale more air relative to their body weight than adults.”

The developing brain goes through significant changes throughout childhood. Processes involved in learning, memory, attention and executive function continue to evolve during these years. Exposure to environmental pollutants during fragile developmental periods is therefore a huge concern.

Also read: Delhi Air Pollution: PM2.5 Exposure May Raise Type 2 Diabetes Risk By 16%, Study Finds

Effects On Learning And Academic Performance

Difficulties in paying attention, memorising and processing complex information can make it harder for children to follow lessons in the classroom.

“Prolonged exposure to high levels of air pollution has been associated with difficulties in concentration, attention, information processing and memory. This may also affect a child's learning abilities and academic performance over time. Although the extent of the impact varies depending on the duration and intensity of exposure, parents should take preventive measures,” says Dr Singla.

What Does Science Say?

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Several studies suggest that air pollution exposure may be associated with poorer cognitive outcomes in children.

A review and meta-analysis published in Environmental Health in 2024 examined six studies involving 4,860 children across North America, Europe and Asia. It found a statistically significant association between higher PM2.5 exposure and lower IQ scores. The researchers reported that every 1 µg/m³ increase in PM2.5 was associated with a 0.27-point decrease in full-scale IQ.

A 2022 review of 86 studies also found evidence between particulate matter exposure and poorer executive function in children, specifically working memory. Executive function refers to a set of mental skills that help children plan, focus attention, remember instructions and manage multiple tasks.

Recent research based on data from the US Adolescent Brain Cognitive Development (ABCD) study also showed that PM2.5 exposure was linked with smaller hippocampal volumes and lower working-memory in young people.

The hippocampus is a brain region involved in learning and memory. The researchers suggested that exposure during both prenatal development and late childhood could affect brain structure and function.

What Can Parents Do?

While individual precautions cannot eliminate the pollution burden, they can help reduce exposure. Dr Singla advises parents to monitor AQI levels, limit outdoor activities during peak pollution hours and ensure adequate indoor ventilation. Other measures include:

• Check air quality before outdoor activities: Avoid outdoor sports, running and strenuous exercise when pollution levels are high.

• Keep windows closed during pollution episodes: Ventilate rooms when outdoor air quality improves. Where possible, use an air purifier with a HEPA filter.

• Use a well-fitting N95 mask: A respirator can reduce exposure to particulate matter when children need to be outdoors.

• Follow school advisories: Parents should stay informed about changes to outdoor classes, sports and school schedules during severe pollution days.