How much water should you drink a day in NHS?

December 27, 2025 •

4 min read

According to the NHS, most people should aim to drink 6 to 8 cups of fluid per day to stay hydrated. Knowing how much water should you drink a day in NHS can significantly impact your health, influencing everything from energy levels to cognitive function.

Quick Summary

The NHS recommends 6 to 8 glasses of fluid daily for most adults, though individual needs vary by activity, climate, and health. All non-alcoholic fluids contribute, with water being the healthiest choice. Monitoring urine colour is a simple way to gauge hydration levels.

Key Points

NHS Recommendation: The NHS suggests most adults drink 6 to 8 cups of fluid daily, approximately 1.2 to 2 litres.
Personalise Your Intake: Factors like exercise, hot weather, and illness increase your need for fluids beyond the general recommendation.
Check Your Urine: The best indicator of adequate hydration is pale straw-coloured urine; dark urine signals a need to drink more.
All Fluids Count: Non-alcoholic drinks like tea, coffee, and milk all contribute to your daily fluid intake, though water is the healthiest choice.
Hydrate with Food: Many fruits and vegetables, such as melon and cucumber, have a high water content and contribute to your overall fluid intake.
Know the Benefits: Good hydration is vital for digestion, brain function, physical performance, and flushing out toxins.
Watch for Dehydration: Symptoms like thirst, dark urine, and tiredness are early warning signs of dehydration.

NHS Recommended Fluid Intake Explained

The National Health Service (NHS) offers clear guidance on daily fluid intake to help people maintain good hydration. For most healthy adults, the recommendation is to drink 6 to 8 cups or glasses of fluid each day. This equates to approximately 1.2 to 2 litres, though it's important to remember this figure is a general guide and not a strict rule. The total fluid can come from a variety of sources, not just plain water, including lower-fat milk, sugar-free drinks, and even tea and coffee. Water, however, remains the best option as it contains no calories or sugar.

Factors That Influence Your Hydration Needs

While the 6 to 8 glasses recommendation is a solid baseline, your personal fluid requirements can change based on several physiological and environmental factors. Your body is constantly losing water through breathing, sweating, and urination, so intake must be adjusted accordingly.

Key factors affecting your daily fluid intake include:

Physical Activity: When you exercise, you sweat, losing a significant amount of fluid. The NHS advises increasing your fluid intake to replace these losses, with water being the best choice.
Weather and Environment: Hot and humid climates cause you to sweat more, increasing your fluid needs. Conversely, air travel and high altitudes can also impact hydration levels.
Health Conditions: Illnesses involving fever, vomiting, or diarrhoea can lead to rapid fluid loss and dehydration, requiring increased fluid intake to replace lost stores. People with certain conditions, like kidney or heart problems, may need specific medical advice regarding fluid consumption.
Age and Life Stage: Older adults may have a reduced sense of thirst, increasing their risk of dehydration. Similarly, pregnant and breastfeeding women have increased fluid requirements.
Diet: The food you eat contributes to your total fluid intake. Water-rich foods like fruits and vegetables can provide up to 20-30% of your daily fluid.

Monitoring Your Hydration Levels

Instead of rigidly counting glasses, the NHS suggests a simpler and more effective method: checking your urine colour. Healthy, well-hydrated urine should be a pale straw yellow colour. If your urine is a darker yellow or strong-smelling, it's a clear sign that you need to drink more fluids. This is one of the most reliable ways to monitor your body's hydration status throughout the day.

Comparison of Hydration Strategies


Feature	Following General NHS Guidelines	Listening Solely to Thirst	Monitoring Urine Colour	Drinking 2 Litres of Water Only
Primary Indicator	Standard 6-8 glasses	Thirst sensation	Urine colour	Fixed volume
Flexibility	Moderate; can be adjusted	High; responsive to needs	High; responsive to needs	Low; inflexible
Environmental Adaptation	Needs conscious adjustment	Naturally adjusts	Naturally adjusts	Needs conscious adjustment
Accuracy	Good for average person	Can be delayed (elderly)	Very high; immediate feedback	Variable; ignores other fluids
Best For	General daily guidance	Most healthy individuals	Precise, personal monitoring	Habit forming; requires awareness of other fluid sources

The Health Benefits of Good Hydration

Staying properly hydrated is crucial for your overall health and well-being. The benefits extend beyond just quenching thirst and include:

Improved Brain Function: Even mild dehydration can impair cognitive function, affecting concentration, memory, and mood. Adequate fluid intake helps maintain mental clarity.
Enhanced Physical Performance: Hydration is key for physical activity, helping to lubricate joints and fuel muscles effectively. It prevents muscle fatigue and reduces the risk of heat-related illnesses.
Digestive Health: Water is essential for proper digestion and helps prevent constipation by softening stools and aiding the digestive system's processes.
Body Detoxification: Your kidneys rely on sufficient fluid to flush out waste products and toxins from your body via urine, supporting overall detoxification.
Healthier Skin: Proper hydration helps maintain skin moisture and elasticity, potentially reducing the appearance of wrinkles.
Reduced Risk of Infections: Good hydration supports kidney function and can help prevent urinary tract infections (UTIs).

Simple Tips for Better Hydration

For many, simply remembering to drink enough can be a challenge. Here are some simple, actionable tips to help you stay consistently hydrated:

Start your day with a glass of water, even before your morning coffee.
Carry a reusable water bottle with you wherever you go as a constant reminder.
Eat your water by incorporating plenty of water-rich fruits and vegetables into your diet, such as cucumber, melon, and lettuce.
Infuse your water with slices of lemon, lime, or cucumber to add flavour if you find plain water boring.
Set reminders on your phone or use a hydration tracking app to prompt you to drink at regular intervals.
Make soup, broth, or porridge for meals, as these foods contain a high water content.

Conclusion

While the general NHS guidance of 6 to 8 glasses of fluid per day provides a solid benchmark for hydration, a person's individual needs can vary significantly based on their activity level, environment, and overall health. The most practical and reliable method for monitoring your hydration is observing the colour of your urine. By adopting a proactive approach to fluid intake and incorporating a variety of hydrating foods and drinks, you can easily meet your needs and reap the wide-ranging health benefits. Prioritise water as your main source of hydration, but remember that other non-alcoholic fluids also count towards your daily total. For a healthy life, stay on top of your hydration game. For more comprehensive health advice, you can consult an NHS GP.

Frequently Asked Questions

The NHS recommends 6 to 8 glasses or cups of fluid a day for most adults. Since a typical glass is 200ml, this equates to roughly 1.2 to 1.5 litres, though some guidelines state up to 2 litres.

Yes, according to the NHS, all non-alcoholic fluids, including tea and coffee, count towards your daily intake. Despite caffeine being a mild diuretic, the fluid content of these drinks is hydrating.

Early symptoms of dehydration include feeling thirsty, having dark yellow and strong-smelling urine, and experiencing a dry mouth, lips, and tongue.

Yes, a significant portion of your daily fluid intake comes from food. Water-rich fruits and vegetables, such as melon, cucumber, and oranges, contribute considerably to your hydration.

Yes, when you are physically active, you lose more fluid through sweating. The NHS advises increasing your fluid intake to replace this loss and maintain performance.

While uncommon for most people, drinking excessive amounts of water in a short period can lead to a condition called hyponatremia, where sodium levels in the blood become dangerously low. Symptoms can include headaches, nausea, and confusion.

The most reliable method is to check the colour of your urine. If it is dark yellow, you need to increase your fluid intake. Waiting until you feel thirsty is often a sign that you are already mildly dehydrated.

Yes, older adults are at a higher risk of dehydration because their sense of thirst can diminish with age. They may need to make a conscious effort to drink regularly, even when not thirsty.