Hydration is vital—full stop. Drinking an adequate amount of water helps support nearly every bodily function, including immune support, temperature regulation, and natural detoxification through the lymphatic system (aka healthy pee).
In an attempt to avoid dehydration, though, some people will overdo their water intake. Here’s why overhydration can be dangerous, how to tell if it’s happening to you, and just how much water you really should be drinking.
What are the dangers of drinking too much water?
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 intoxication, 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 hyponatremia (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.
This seemingly crazy phenomenon is more common for people going through intense training programs, including triathlon or ultramarathon runners, members of the military, or professional athletes. According to the U.S. National Library of Medicine, extreme thirst could also be triggered by medications like diuretics, or a symptom of high blood sugar. ADVERTISEMENT
Signs you’re drinking too much water (aka symptoms of overhydration):
1. Your pee is clear.
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.
If this is the case, don’t panic. It’s not always dangerous to have clear urine, Simma-Chiang says. However, it is the body’s way of signaling that you’ve had plenty to drink. Take note of that, and hold off on sipping until you feel thirsty again.
2. You’re going pee a lot more frequently than normal.
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?”
Aside from the dangers of overhydration, going back and forth to the bathroom all day long is distracting, and having your sleep disrupted by a full bladder can be even worse.
3. Your muscles are cramping.
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.
To replace electrolytes, Waldrop recommends drinking an electrolyte-infused beverage, taking electrolyte supplements, or eating a snack that contains electrolytes. “A banana with salted peanut butter could be a good option,” she suggests.
4. You’re drinking when you’re not thirsty.
“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.
Unless you’re feeling thirsty, or your throat and mouth are dry, you probably don’t need to take that extra sip (or chug). One way to keep track of this is by keeping a voiding diary: what you’re drinking and how much you’re drinking, she says.
5. You’re experiencing more severe symptoms.
“Signs of overhydration include nausea, vomiting, headache, and mental confusion,” Waldrop says. “Commonly, people can also experience fatigue, muscle cramping, lightheadedness, and dizziness. In very severe cases, seizure, coma, or death can result.”
How much water should you be drinking?
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.”
Certain diseases, particularly in the kidneys, can also make it difficult to process fluids and electrolytes, she adds. If you think (or know) you’re affected by this, it’s a good idea to consult a doctor.
As critical as hydration is, overhydration has its dangers. Moderating your water intake and keeping an eye on your urine color are two helpful ways to avoid unwanted side effects of excess fluid consumption.