Overhydration: Is It Possible to Drink Too Much Water?

Signs and symptoms of hyponatremia

Your body is made up of about 70% water, with your brain tissue being 80% water. This means that staying hydrated is essential to ensure that your body and brain function properly, and even more so, at a peak level.

During the day, you lose water from your skin (sweating), through respiration, in your bowel movements, and through urinary output1. How much urine you produce a day is determined by how much water you drink and the maximum amount your renal system can hold.

On average, considering diet, exercise, and the climate of where you live, the minimal urine output for healthy people is about 500 ml/day1.

Though there isn't a specific guideline to how much water you should drink per day, the most often used average is about 3 liters a day for men and 2.2 liters a day for women. Your body will need more water if you are in hot climates, exercising, or sick (think: fever, diarrhea, or vomiting)6. It's also important to note that everyone's needs are different. Drinking more than this recommended amount has yet to have any concrete health benefits (except maybe to prevent kidney stones)1.

Water keeps the systems in your body functioning properly, it3:

  • Carries nutrients and oxygen to cells
  • Gets rid of waste (flushes bacteria from the bladder)
  • Aids digestion (prevents constipation)
  • Helps normalize blood pressure
  • Lubricates joints
  • Protects the spine, brain, and other organs and tissues
  • Regulates body temperature
  • Helps maintain sodium levels

Drinking enough water every day to prevent dehydration is essential for your health. If you become dehydrated, you could start thinking unclearly, have mood changes, and your body could overheat. It could also cause conditions such as constipation and kidney stones6. Most of your fluid intake will be from the water you drink. But, you can also meet your body's needs with a combination of other beverages and foods you eat (most fruits and vegetables have high water content!)

You might be suffering from dehydration if you're:

  • Thirsty
  • Urinating dark yellow and strong-smelling pee
  • Feeling dizzy or lightheaded
  • Tired
  • Peeing too little in a day
  • If your mouth, lips, and eyes are dry

But what happens if you drink too much water?

It's important to recognize that water intoxication alone is very unlikely to cause fatal hyponatremia. It's most often found in people that do not have a standard, regular working renal system2. The condition is often unrecognised in the early stages. People are usually confused, disorientated, nauseous, and vomiting. They also have changes in their mental state (psychotic symptoms). Drinking too much water can lead to seizures, coma, and in severe cases, death1.

Early detection is vital in preventing fatal cases of hyponatremia.

As its name suggests, water intoxication happens from drinking more water than your body can handle in a specific time period. The excess water in the body ends up diluting the sodium in your blood. Once sodium levels in your blood fall too low, the extra fluid moves inside the cells. The cells then end up expanding and swelling.

Again, usually, the body can excrete any extra water drank through urine or sweat. Water toxicity only happens when the kidneys can't keep up with the amount of water arriving in the body3. According to a 2013 study, kidneys can eliminate around 20–28 liters of water per day. However, they can only excrete approximately 0.8 to 1.0 liters per hour4.

Are you at risk for hyponatremia?

Water toxicity is rare and is usually only seen in individuals whose kidneys and renal systems are not functioning correctly. However, it can also happen if you are in extreme heat stress or taking part in lengthy exercise routines, or challenges such as triathlons or marathons. Athletes should be aware of the signs and symptoms of water toxicity as they are in a higher risk category than most.

Children are at higher risk as well due to their smaller body size.

To avoid hyponatremia, it is important not to drink more water than your kidneys can handle.

If you or any other person think you have hyponatremia, you should consult with your doctor or other professional medical health advisors. If you think it’s a medical emergency, call emergency services immediately.


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