The advice to drink eight glasses of water every day has been around for decades and is a popular health mantra. However, there’s a lot of debate about whether we really need this much water and whether the advice applies to everyone.

What Happens When We Don’t Drink Enough Water?

Several studies have shown that even mild dehydration can affect our cognitive function and mood. Some common signs of dehydration include:.

Thirst
Dry mouth and throat
Headache
Dizziness and fatigue
Dark urine

So, it’s important to stay hydrated to maintain our physical and mental health. However, the question remains: do we really need eight glasses of water every day?.

Does the “Eight Glasses a Day” Rule Apply to Everyone?

There’s no one-size-fits-all answer to this question, as the amount of water your body needs depends on many factors, including:.

Your age
Your sex
Your weight and height
Your activity level
Your environment
Your overall health

For example, a person who is physically active and sweats a lot will need more water than someone who is sedentary and doesn’t sweat much.

Similarly, a person who lives in a hot and humid climate will need more water than someone who lives in a cold and dry climate.

In general, the Institute of Medicine (IOM) recommends that men drink about 3.7 liters (or about 13 cups) of water per day, and that women drink about 2.7 liters (or about 9 cups) per day.

However, these recommendations also include water we get from food and other beverages, such as coffee and tea.

Is It Possible to Drink Too Much Water?

In some cases, drinking too much water can actually be harmful to our health. This is known as water intoxication, or hyponatremia. This occurs when the level of sodium in our bloodstream becomes too diluted, leading to symptoms such as:.

Nausea and vomiting
Headache
Confusion and disorientation
Seizures and coma (in severe cases)

Water intoxication is more common in endurance athletes who drink excessive amounts of water during long and intense training sessions or competitions. However, it’s generally not a concern for most people who drink water in moderation.

How Can We Tell if We’re Drinking Enough Water?

If you’re not sure whether you’re drinking enough water, here are some signs to look for:.

Your urine is a pale yellow or straw color.
You don’t feel thirsty on a regular basis.
You’re able to produce enough saliva and tears.
You don’t experience frequent headaches or constipation.

If you notice any of these signs of dehydration, increase your water intake gradually until you start to feel better.

Conclusion

While the “eight glasses a day” rule may not be applicable to everyone, it’s important to stay hydrated to maintain our physical and mental health.

Your body needs water to carry out many essential functions, such as regulating body temperature, removing waste, and lubricating joints.

If you’re not sure how much water you need, talk to your doctor or a registered dietitian. They can help you determine the right amount of water for your individual needs based on your age, sex, weight, activity level, and overall health.