What is overhydration?
Overhydration is an excess of water in the body. Overhydration occurs when the body takes in more water than it loses.
Overhydration can occur when people drink much more water than their body needs. People, particularly athletes, who drink excessive water to avoid dehydration can develop overhydration, but usually do not. Often, people drink excessive water because of a psychiatric disorder called psychogenic polydipsia. The result is too much water and not enough sodium. Thus, overhydration generally results in low sodium levels in the blood (hyponatremia), which can be dangerous. However, drinking large amounts of water usually does not cause overhydration if the pituitary gland, kidneys, liver, and heart are functioning normally. To exceed the body’s ability to excrete water, a young adult with normal kidney function would have to drink more than 23 liter of water a day on a regular basis.
How common is overhydration?
Overhydration is much more common among people whose kidneys do not excrete urine normally—for example, among people with a disorder of the heart, kidneys, or liver, or among premature infants, whose kidneys are immature. Please discuss with your doctor for further information.
What are the symptoms of overhydration?
Brain cells are particularly susceptible to overhydration and to low sodium levels in the blood. When overhydration occurs slowly and is mild or moderate, brain cells have time to adapt, so only mild symptoms (if any) like distractibility and lethargy may ensue. When overhydration occurs quickly, and whenever dehydration is severe, confusion, seizures, or coma may develop.
When overhydration occurs and blood volume is normal, the excess water usually moves into the cells, and tissue swelling (edema) does not occur. When excess blood volume occurs, fluid can accumulate in the lungs and lower legs.
There may be some symptoms not listed above. If you have any concerns about a symptom, please consult your doctor.
When should I see my doctor?
If you have any signs or symptoms listed above or have any questions, please consult with your doctor. Everyone’s body acts differently. It is always best to discuss with your doctor what is best for your situation.
What causes overhydration?
Overhydration is an imbalance of fluids. It happens when your body takes in or holds on to more fluid than your kidneys can remove.
Drinking too much water or not having a way to remove it can cause water levels to build up. This dilutes important substances in your blood. Endurance athletes, such as those who run marathons and triathlons, sometimes drink too much water before and during an event.
The Institute of Medicine established guidelines for adequate water intake. They recommend that a healthy adult drink 2.3 liter to 2.9 liter (about 9–13 cups) of fluids per day, on average.
It’s also important to remember that water needs vary with age, sex, weather, activity level, and overall health. So there is no exact formula on how much to drink. Common situations such as extreme heat, significant activity, and illness with fever will all require more fluid intake than average.
In a healthy person, your urine is a good indicator of your hydration status. Pale yellow urine that looks like lemonade is a good goal. Darker urine means you need more water. Colorless urine means you are overhydrated.
In healthy people, athletes are at highest risk for overhydration. Sports experts at Harvard recommend that a logical approach to hydration while exercising is letting thirst be your guide.
Some conditions and medicines cause overhydration by making your body hold on to more fluid. These include:
- Congestive heart failure (chf)
- Liver disease
- Kidney problems
- Syndrome of inappropriate antidiuretic hormone
- Nonsteroidal anti-inflammatory drugs
- Uncontrolled diabetes
Other conditions and drugs can cause increased water intake by making you extremely thirsty. These include:
- MDMA(commonly known as ecstasy)
- Antipsychotic drugs
What increases my risk for overhydration?
Overhydration is more common among endurance athletes who drink large amounts of water before and during exercise. It has been reported among:
- People who run marathons and ultramarathons (races longer than 42km)
- Ironman triathletes
- Endurance cyclists
- Rugby players
- Elite rowers
- Military members involved in training exercises
This condition is also more likely in people with kidney or liver disease. It can also affect people with heart failure.
Diagnosis & treatment
The information provided is not a substitute for any medical advice. ALWAYS consult with your doctor for more information.
How is overhydration diagnosed?
- A doctor’s evaluation
- Blood tests
Doctors try to distinguish between overhydration (too much water) and excess fluid in the blood (too much salt and increased blood volume) by examining the person for signs of edema and doing blood tests to check the concentrations of electrolytes.
How is overhydration treated?
Regardless of the cause of overhydration, fluid intake usually must be restricted (but only as advised by doctors). Drinking less than a quart of fluids a day usually results in improvement over several days. If overhydration occurs with excess blood volume because of heart, liver, or kidney disease, restricting the intake of sodium is also helpful because sodium causes the body to retain water.
Sometimes, doctors prescribe diuretics to increase the excretion of sodium and water in the urine. Other types of drugs also can increase water excretion and are sometimes used to treat overhydration when blood volume is normal. These drugs are generally used when a person is in the hospital and can be carefully monitored.
Lifestyle changes & home remedies
What are some lifestyle changes or home remedies that can help me manage overhydration?
The following lifestyles and home remedies might help you prevent overhydration:
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. It is recommended to drink 16 to 20 ounces of fluid for every pound lost.
While exercising, try to drink 2 to 4 cups of fluid per hour. If exercising longer than an hour, sports beverages are also an option. These drinks contain sugar, along with electrolytes such as sodium and potassium, which you lose in sweat. Let thirst also guide you when exercising. If you’re thirsty, drink more.
If you have a medical condition such as diabetes, CHF, or kidney disease, talk to your doctor about the best treatments. Also contact your doctor if you’re unusually thirsty. This could be a sign of a medical problem that needs to be treated.
If you have any questions, please consult with your doctor to better understand the best solution for you.
Hello Health Group does not provide medical advice, diagnosis or treatment.
Review Date: October 27, 2017 | Last Modified: December 9, 2019
Overhydration. https://www.healthline.com/health/overhydration#overview. Accessed October 27, 2017.
Overhydration. http://www.msdmanuals.com/home/hormonal-and-metabolic-disorders/water-balance/overhydration. Accessed October 27, 2017.