There’s no doubt about it, drinking enough water to stay hydrated is important for many reasons — such as preventing fatigue, regulating blood pressure and even controlling hunger. But can you have too much water?
The answer is yes, you definitely can. In fact, water intoxication (a severe form of hyponatremia) is considered to be a life-threatening emergency that must be diagnosed and treated promptly to prevent serious complications. Below we’ll look at the dangers associated with drinking too much water, plus how much water should actually be consumed daily for optimal hydration.
Water intoxication is referred to in a few different ways, including: hyponatremia, water poisoning, hyperhydration, or excessive water intake. All of these terms describe the same serious health condition that is caused by an electrolyte imbalance — specifically having too much water (H2O) in the blood in relation to sodium.
Hyponatremia means low sodium levels in the blood (the term, which has Latin and Greek roots, literally means “insufficient salt in the blood”). Water intoxication, or hyponatremia, is the opposite of hypernatremia, the condition that occurs due to dehydration (low levels of body water).
Because it’s preventable, you might be wondering in what types of situations is water intoxication most likely to occur? Studies have found that this condition commonly develops in hospitalized patients and those with mental disturbances, although it can also affect people who are otherwise healthy. Water intoxication has been described in several different clinical situations:
Because water intoxication messes with normal neurological functions and nerve signaling, it can manifest as a psychotic illness in its early stages that can go unrecognized by doctors. For example, if someone is admitted to the emergency room for water intoxication medical providers might mistake the patient’s symptoms for a high fever, seizure, or mental disorder such as chronic paranoid schizophrenia.
Water intoxication doesn’t just affect adults; it can also occur in babies, especially those under 9 months old, and in children. Symptoms of water intoxication in babies or children can include: crying, changes in behavior, vomiting, twitching or shaking, irregular breathing, and, in severe cases, seizures, coma, brain damage and death.
Some of the negative health impacts associated with water intoxication include:
While staying hydrated is important, there’s also such a thing as a fatal water overdose. In severe cases, hyponatraemia that is not treated can lead to seizures, coma and death. This is why experts say that early detection is crucial for preventing severe hyponatremia. How severe water intoxication becomes depends on how much and how quickly water was consumed, and the rate at which the sodium concentration in the blood falls. For water intoxication symptoms to be experienced someone would have to drink more than five cups of water per hour.
Several factors can affect how well someone is able to excrete (remove) excess water from their body in order to prevent hyponatremia/water intoxication. For example, as mentioned above, being under a lot of stress and/or having existing medical conditions both take a toll on the kidneys and nervous system, which can increase the likelihood that water intoxication symptoms might occur.
Treatment for hyponatremia and water intoxication comes down to regulating fluid levels in the body, specifically raising sodium levels. Intake and excretion of salt versus water must be balanced. Keep in mind that while sodium/salt might have earned a bad reputation — mostly because it’s found in highest concentrations in processed foods — sodium is actually an essential nutrient. For example, some of the roles that sodium has include:
Even though drinking too much water and experiencing overhydration can be very dangerous, this doesn’t mean that you shouldn’t drink water regularly throughout the day. Dehydration (or hypernatremia) causes its own set of health problems. In fact, many dehydration symptoms are similar to the symptoms of water intoxication.
Water (H2O) makes up more than 60 percent of the human body, so it’s no surprise that we need a steady supply of water to function optimally. (10) Everyday we lose water through a combination of urine, defecation/bowel movements, sweat and exhaled breath. Staying hydrated is important because it helps prevent symptoms like:
People who should be especially careful to drink enough water/fluids (but not too much) are:
How much water is safe to drink at a time? To put this another way, how much water is too much to drink in one hour?
>To prevent hyponatremia from developing and potentially progressing to water intoxication, it’s important to:
In regards to how much water to drink daily, the most common advice is to drink eight, eight-ounce glasses of water per day. However, this is just a general recommendation and not necessarily the best amount for every person. In fact, according to a 2002 review published in the American Journal of Physiology —Regulatory, Integrative and Comparative Physiology, there isn’t much scientific evidence to support drinking this amount. (11)
Each person is a bit different in terms of how much water they need, but overall it’s best to aim for about six to seven glasses or potentially more per day (8 ounces per glass). You might need less if you eat a water-rich diet, such as lots of fruit, salads and smoothies. And you might need more if you exercise frequently, live in a hot climate, are ill, or eat a salty diet. Rather than counting glasses of water, pay attention to how you feel. A good way to know if you’re drinking the right amount of water each day is to pay attention to the color of your urine: you want your urine to normally be a pale-to-medium yellow color, as opposed to clear or very dark yellow/orange.
In terms of the best water to drink, I recommend using a water filter at home rather than drinking contaminated tap water or bottled water. Why? A three-year study conducted by the Environmental Working Group found 316 chemicals can be found in tap water throughout the U.S! Using an at-home filter is your best bet because this helps remove toxins that might be lingering in the water supply. There are several different types of water filters, including:
Choose the option that works best with your family’s lifestyle and that will be easiest to use consistently.
Parents might think it’s a good idea to give their young children water and other fluids to prevent dehydration, but when a baby is breast-feeding the mother’s breast milk or formula actually provides all the fluid healthy babies need. The Johns Hopkins Children’s Center advises parents with babies younger than 6 months old to never give their babies extra water to drink. If babies are thirsty, they need to drink more breast milk or formula. (12)
According to James P. Keating, MD, the retired medical director of the St. Louis Children’s Hospital Diagnostic Center, if a baby seems to need additional water then parents should “limit the child’s intake to two to three ounces at a time, and water should be offered only after the baby has satisfied his hunger with breast-feeding or formula.” (13) Older babies can be given small amount of water at times to help prevent constipation or if they are in very hot weather, but it’s usually best for parents to discuss this with their pediatrician.
Children up to about 8 years old should get water from hydrating foods in their diet (like fruits and veggies) or drink the equivalent of about five to seven glasses of water per day (eight ounces per glass). (14) Water or fresh-squeezed juice in small amounts is the best thing for children to drink when they are thirsty, rather than sugary fruit drinks, soft drinks, sports drinks, iced tea and flavored beverages.
If you suspect that you or someone else is experiencing water intoxication, then visit the emergency room for help right away. Look out for sudden symptoms of an electrolyte balance like confusion and dizziness, especially after high-intensity activities or if you have conditions like low blood pressure and/or diabetes. Make sure you drink the proper amount of water during a hospital stay, after surgery, when partaking in a marathon/long-distance race, or during a bout of dehydration or illness (like a fever).