Health experts say that the average person should drink eight 8-ounce (236.6-mL) glasses of water daily. Exactly how much water you should drink each day can depend on how big you are, however. Some healthcare professionals recommend drinking half an ounce (14.8 mL) per 1 pound (0.45 kg) of body weight. For example, if you weigh 150 pounds (68 kg), you should drink 75 ounces (2.2 liters) of water daily. Other factors that can affect how much water you should drink daily include your physical activity level, the climate where you live, your diet and certain other health or medical factors.
If you are active in sports or the weather is warm or humid where you live, you should add more water to your daily drinking quota. This is because your body will lose fluids as you sweat. Drinking sufficient amounts of water will replenish the fluid level in your body. Many health experts also recommend drinking distilled water instead of tap water, which might contain chlorine or other impurities.
Other Sources of Fluids
It is often said that a person needs to drink less water daily if he or she consumes watery foods, such as soups or melons. Others believe that drinking other beverages will reduce the amount of water that a person needs to drink daily. There is believed to be some truth to these theories, but the extent to which other types of fluid can be counted toward a person's daily water intake is a matter of debate among many healthcare professionals.
Some health experts say that the body processes watery foods and other beverages in a way that is different from the way it processes water, so substituting other types of fluids for water does not provide adequate hydration. Most experts agree, however, that plain water is the best source of fluids. This is because it contains no calories or additives, it is inexpensive, and it is readily available in most parts of the world.
Effects of Medical Conditions
Women who are pregnant or breastfeeding, people who are suffering from illnesses that cause vomiting or diarrhea and people who are trying to lose weight typically should drink more water daily. Certain other medical conditions, such as bladder infections, also should be treated with an increase in water consumption. Increasing water intake not only replenishes the body's fluids, it also helps the body flush out unwanted substances. For example, burning fat to lose weight creates waste products that must be flushed from the body. Drinking more water daily will help remove these toxins from the body.
Some people who suffer from water retention, also known as bloating, are reluctant to drink extra water because they think that it will make the bloating worse. Retaining water, however, is often a sign that the body is not getting enough water, causing it to hoard what little water it has. Counter-intuitively, even if you feel bloated or your ankles are swollen, drinking more water will actually help you shed the excess fluids that are stored in your tissues.
It is possible to overdose on water. Too much water can throw the body's electrolytes out of balance and can cause many types of symptoms, including headache, cramping, nausea, confusion and vomiting. In some instances, it can even be fatal. Water intoxication, also called water poisoning, is very rare, however, and occurs mostly under unusual circumstances and when enormous amounts of water are consumed within a short period of time.