From feeling less tired to clearing up spots, drinking enough water can cure all sorts of ills.
But the majority of people simply don't drink enough of it.
Medical research centre the Mayo Clinic in Minnesota reveals that men should be drinking 13 cups of it a day on average, while women could consume nine.
But every person's body is different - and the amount you really need to drink can be worked out using a simple formula.
The equation is said to work by taking your weight and multiplying it by your age. From there, divide the number by 28.3 and you'll get the recommended ounces of water, which can be divided by eight to measure the number in to cups.
However if you exercise regularly, you'll of course need to drink even more water to replace the liquid you'll lose through sweat.
The American College of Sports Medicine reports that you should drink an extra 12 ounces of water for every 30 minutes of exercise.
Your diet can play a large role in helping to keep you hydrated.
Eating foods with a high water content, such as watermelon, cucumber and celery, can help flush out toxins in your body.
However, eating salty foods can do the opposite as your body will retain fluids to help dilute the sodium you've just consumed - which is why we often bloat after eating sodium-rich foods, and get thirsty.