Hydration and its role in overall health

Water is often called the “elixir of life,” and for good reason. Every cell, tissue and organ in the human body relies on water to function. From regulating body temperature to aiding digestion, from cushioning joints to maintaining healthy skin, hydration plays a crucial role in overall health and well-being.

Yet, despite it is important, many people underestimate their daily fluid needs or fail to recognise the signs of dehydration until it becomes a problem.

This blog delves into the science of hydration, its vital role in maintaining health, common myths, signs of dehydration, and practical strategies for staying adequately hydrated.

Why hydration matters

The human body is composed of approximately 60–70% water, depending on age, sex and body composition. Water is essential for

• Nutrient transport: Carrying vitamins, minerals, and glucose to cells.
• Temperature regulation: Sweating and evaporation help maintain a stable body temperature.
• Waste elimination: Flushing out toxins through urine, sweat, and bowel movements.
• Joint lubrication: Reducing friction to prevent wear and tear.
• Cellular health: Supporting the structure and chemical balance of every cell.

Even mild dehydration—losing as little as 2% of body weight in fluids—can negatively impact mood, energy levels, and cognitive performance.

Hydration and body systems

1. Brain and mental function

The brain consists of approximately 75% water, and dehydration can directly impact mental clarity and concentration. Research shows that even slight dehydration can impair short-term memory, alertness and mood. Adequate hydration keeps the brain energised, reduces fatigue and enhances productivity.

2. Heart and circulation

Blood is roughly 90% water. When you’re dehydrated, blood volume decreases, forcing the heart to pump harder to deliver oxygen and nutrients. It can increase heart rate, lower blood pressure and in severe cases, contribute to fainting or cardiovascular strain.

3. Kidneys and detoxification

The kidneys filter waste products from the blood and maintain electrolyte balance. Proper hydration helps prevent kidney stones, urinary tract infections and chronic kidney disease. Insufficient water intake leads to more concentrated urine, increasing the risk of stone formation and infections.

4. Digestive health

Water is necessary for saliva production, nutrient absorption, and smooth bowel movements. Dehydration can cause constipation, indigestion, and acid reflux. Drinking adequate water supports gut motility and reduces bloating.

5. Skin and appearance

Hydrated skin looks plump, elastic, and radiant. Chronic dehydration contributes to dryness, premature wrinkles and dullness. While topical skincare matters, true skin health begins from within—with proper hydration.

6. Muscles and joints

Muscles require water to contract efficiently and joints need it for lubrication. Dehydrated muscles fatigue more quickly and are more prone to cramps, while insufficient fluid can make joints feel stiff or sore due to a lack of cushioning.

Recommended daily water intake: How much do you really need?

The popular “8 glasses a day” rule is oversimplified. Fluid requirements can vary based on age, activity level, climate, and overall health. According to the National Academies of Sciences, Engineering, and Medicine (NASEM)

• Men: Approx 3.7 litres (15.5 cups) of fluids per day
• Women: Approx 2.7 litres (11.5 cups) of fluids per day

These totals include fluids from beverages and foods, not just plain water. For example, cucumbers, watermelon, oranges, and spinach are water-rich foods that contribute to hydration.

Hydration and special conditions

1. Exercise and physical activity

During exercise, the body loses fluids through sweat. Athletes may need significantly more water and electrolytes to replace what’s lost. Sports drinks can be beneficial during prolonged, high-intensity activities, but for most people, plain water is sufficient.

2. Climate and environment

Hot, humid weather increases sweating, while cold environments may suppress thirst signals, leading to unnoticed dehydration. At high altitudes, rapid breathing and low humidity also lead to fluid loss.

3. Pregnancy and breastfeeding

Pregnant women need extra fluids to support fetal development and amniotic fluid. Lactating mothers require additional hydration for milk production.

4. Medical conditions

• People with kidney stones, UTIs, or gout benefit from increased water intake.
• Some medications, such as diuretics, increase urine output and may require more careful attention to hydration.
• Patients with heart failure or advanced kidney disease may need restricted fluid intake—always under medical supervision.

Dehydration: Causes, symptoms and risks

Causes

• Inadequate fluid intake
• Excessive sweating
• Fever, vomiting, or diarrhoea
• High salt intake
• Alcohol and caffeine over consumption

Early symptoms

• Thirst
• Dry mouth and lips
• Dark yellow urine
• Fatigue
• Headache

Severe dehydration

• Dizziness or fainting
• Rapid heartbeat
• Sunken eyes
• Very little or no urination
• Confusion or irritability

If untreated, severe dehydration can lead to heatstroke, seizures, kidney damage, or even death.

Hydration myths vs facts

1. Myth: Coffee and tea dehydrate you.

Fact: While caffeine is mildly diuretic, moderate consumption still contributes to hydration.

2. Myth: You only need water when you’re thirsty.

Fact: Thirst is a late sign of dehydration, especially in children and older adults.

3. Myth: Clear urine is always a sign of perfect hydration.

Fact: Clear urine can also mean overhydration, which dilutes essential electrolytes.

4. Myth: More water is always better.

Fact: Drinking too much water can lead to hyponatremia, a condition characterised by low sodium levels in the blood, which can be dangerous.

Balance is key.

Practical tips to stay hydrated

• Start your day with water – Drinking a glass upon waking helps rehydrate after hours of sleep.
• Carry a reusable water bottle – Keeping water within reach encourages you to sip throughout the day.
• Flavour naturally – Add lemon, cucumber, or mint for taste without sugar.
• Eat water-rich foods – Include fruits, vegetables, and soups in meals.
• Set reminders – Use smartphone alarms or apps to monitor your water intake.
• Balance electrolytes – Especially after exercise or illness, replenish with coconut water, electrolyte drinks, or oral rehydration solutions.
• Adjust with seasons – Drink more during the summer or in heated indoor environments during winter.
• Listen to your body – Pay attention to thirst, urine colour, and energy levels.

Hydration and long-term health

Proper hydration is not just about avoiding thirst; it has long-term health implications

• Kidney health: Reduces the risk of stones and chronic kidney disease.
• Weight management: Drinking water before meals may reduce calorie intake and aid weight control.
• Heart health: Supports circulation, reduces strain on the cardiovascular system.
• Metabolism: Adequate hydration boosts energy expenditure slightly, supporting metabolic health.
• Healthy ageing: Older adults often lose their sense of thirst; staying hydrated lowers risks of confusion, falls, and constipation.

In a nutshell

Hydration is one of the most cost-effective and most powerful steps you can take to support overall health. From sharper thinking and better energy to healthier skin, joints, and organs, the benefits of proper water intake are undeniable.

Since hydration needs differ for everyone, maintaining a routine of water, healthy drinks, and hydrating foods can improve overall well-being and help prevent many common health problems.

So, the next time you reach for a glass of water, remember: you’re not just quenching thirst, you’re fueling your body, protecting your organs, and investing in a healthier future.