Almost all of the major systems of your body depend on water to work properly. Drinking plenty of water helps your body regulate body temperature, prevent constipation, flush waste products out of the body, and perform many other important functions.
Most people, especially those who exercise in hot weather, are more concerned about not drinking enough water. However, overhydration, or drinking too much water, is also a potentially deadly condition. It can throw off the balance between water and sodium in your blood.
There are two types of overhydration:
Increased water intake
Drinking more water than the kidneys can get rid of in the urine can cause too much water to collect in the body.
When the body is unable to get rid of excess water, it is said to be retaining water. This happens with several medical conditions, for instance. It can be dangerous because it throws off the balance between water and sodium in the blood.
Overhydration can be caused by drinking too much water. This can occur both consciously and unconsciously. For example, a person may drink too much water during exercise. Some medications can also cause dry mouth and an increase in thirst. Increased thirst can also be caused by uncontrolled diabetes. Psychiatric conditions such as schizophrenia can also cause compulsive water drinking.
Overhydration can also be caused by water retention. This is often the result of medical conditions, such as:
- liver disease
- kidney problems
- congestive heart failure
- syndrome of inappropriate anti-diuretic hormone
You may not recognize symptoms of overhydration in the early stages. Common symptoms include:
- nausea and vomiting
- changes in mental state such as confusion or disorientation
Untreated overhydration can lead to dangerously low levels of sodium in the blood. This can cause more severe symptoms, such as:
- muscle weakness, spasms, or cramps
Your doctor will ask about your medical history to determine whether symptoms are caused by overhydration or another condition. They will also perform a physical examination, and they may order blood and urine tests.
Treatment for overhydration depends on the severity of the symptoms and the underlying reason. It may include:
- cutting back on your fluid and salt intake
- diuretics to increase how much urine is produced
- medications to reduce symptoms such as nausea, seizures, and headache
- treatment of underlying medical conditions
Endurance athletes can reduce the risk of overhydration by weighing themselves before and after a race. This helps determine how much water they have lost and need to replenish.
You should avoid drinking more than one liter per hour of fluid. Drinking more fluids before and during an intense athletic performance can also help you avoid the need to drink too much water afterwards. Sports beverages that contain the electrolytes sodium and potassium are also recommended, as both are lost in sweat.
If you have an underlying medical condition, such as diabetes, congestive heart failure, or kidney problems, talk to your doctor about the best treatments for those conditions. If you have excessive thirst, contact your doctor. This could indicate a medical problem that requires treatment.