How To Tell If You're Experiencing Overhydration, According To Doctors

Hydration is vital—full stop. Drinking an adequate amount of water helps support nearly every bodily function, including immune support, temperature regulation1, and natural detoxification through the lymphatic system (aka healthy pee).

Drinking water excessively can have a number of side effects, including muscle cramping from electrolyte imbalance and an increase in urine frequency. In extreme cases, drinking too much water can lead to fatal water intoxication2, also known as water toxemia, water poisoning, or hyperhydration. 

"In overhydration an excess of water dilutes the electrolyte concentrations in the blood, causing imbalance throughout the body's many systems," physician Catherine Waldrop, M.D., tells mbg. Electrolytes, like sodium, potassium, magnesium, and calcium, are charged ions essential for many cellular processes. "When the concentration of electrolytes in the blood is too low, it makes nearly all cellular processes less efficient to nearly impossible," she says. 

The most common electrolyte imbalance, which can be caused by drinking too much water, is called hyponatremia3 (aka low sodium in the blood). "Mild hyponatremia is characterized by gastrointestinal tract symptoms, nausea, vomiting, loss of appetite," one study says, whereas, more serious cases result in excess water and swelling in the brain, leading to seizures, comas, or impaired mental status.

One way to keep track of your water intake is by looking at the color of your urine. According to urologist Vannita Simma-Chiang, M.D., a light yellow is the ideal pee color. 

"If your urine is a really dark yellow, you're probably not drinking enough," she previously told mbg. But if your urine is clear, that's a sign you're drinking way too much. "At that point, your body is just dumping water," she says.

The average, healthy person will pee every three to four hours, Simma-Chiang says. Any more than that, there's a good chance they're overhydrating. When you drink too much water, you're driving that process of water in, water out, she says. "It's gotta go somewhere, right?"

Because of the electrolyte imbalance, namely low sodium, it's not uncommon to experience muscle cramping, weakness, or spasms, as a side effect of overhydration. "When the body sweats, both water and electrolytes are secreted on the skin, so it's essential to keep replacing both to avoid both dehydration and overhydration," Waldrop says.   

"Everybody wants to be healthy, and one way to be healthy is to stay hydrated," Simma-Chiang says. "But people can take it to an extreme." For example, drinking from a gallon water bottle every day is probably too much for the average person. 

The "right" amount of water varies from person to person, depending on age, sex, activity level, and more, so there's no direct answer to this. In general, drinking water when you feel thirsty or any time you're losing fluids (think sweating or when you're sick), or if your urine appears dark yellow, it's a good idea to grab for the water. 

"People who live in hot and/or dry climates or are very physically active will likely need higher levels of fluid intake," Waldrop says. "Women who are pregnant or nursing will also likely need to drink more fluids."