Experts Explain Why You’re Still Dehydrated After Drinking Water All Day

A woman drinks a large nalgene while doing yoga in her living room. Experts explain reasons you're s...
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You often hear the old "eight glasses of water a day" adage as a way to stay hydrated. But unfortunately, hydration is not as simple as refilling your Nalgene. It's possible to still be dehydrated after drinking water. This may be discouraging for avid H2O drinkers, but if you drink a lot of water and still feel dehydrated, you can pinpoint the source of the problem and become hydrated again.

"Hydration is essential to overall health," board-certified rehabilitation specialist Scott Michael Schreiber, D.C., tells Bustle. "Many Americans are chronically dehydrated, which means they have been drinking less than optimal for a long period of time. When this occurs, you need to slowly rehydrate, as your body has been in survival mode, adjusted to not consuming enough water. In addition, as you drink more, you will go to the bathroom more. This will pass with time as your body becomes more hydrated."

The biggest signs that you're dehydrated include inability to sweat, dry skin, bad breath, dark pee, and urination less than six times a day. It might be confusing if you're experiencing these signs even after drinking lots of water, but drinking water isn't all that it takes to stay hydrated. Here are some reasons you might be dehydrated despite seemingly adequate water intake, according to experts.


You're Missing Electrolytes

"You may be drinking enough water but still have feelings of dehydration if you have an electrolyte imbalance," Dr. Natasha Trentacosta M.D., a sports medicine specialist and orthopedic surgeon at Cedars-Sinai Kerlan-Jobe Institute, tells Bustle. Electrolytes like sodium, chloride, magnesium, and potassium are necessary to deliver fluids to your cells. "Consuming water, especially in excess, can flush out electrolytes and fiber," Dr. Trentacosta says. "Similarly, excessive sweating from strenuous exercise results in a loss of electrolytes." She recommends focusing on drinks with a lot of electrolytes, like coconut water, and eating fruits and vegetables with a lot of fiber to combat these losses.


You're Not Drinking Often Enough

If you drink a ton of water in one sitting, that won't hydrate you as well as drinking often throughout the day. "When you are thirsty, you are already heading down the road to dehydration," says Schreiber. "You need to be drinking water all day long, as opposed to only when you are thirsty. Your body will absorb more water over the course of the day, rather than at one shot!"

"It can be helpful to keep track of the amount of water intake throughout the day to make sure you are taking in enough fluids," Dr. Trentacosta says. Think about getting a water container that marks off fluid amounts, or using an app.


It Could Be A Sign Of Diabetes

"If you are constantly feeling dehydrated and urinating excessively, this may be the first sign of diabetes," Dr. Trentacosta says. Because their bodies are trying to get rid of sugar, people with diabetes pee frequently, which can dehydrate them. If you find yourself always thirsty and peeing a lot, it may be worth it to get tested for diabetes.


You're Drinking Dehydrating Fluids

Even if you're drinking water, you can still be dehydrated, because certain drinks can cancel it out: coffee and soda are particular culprits. The National Health Service notes that while a small amount of coffee won't dehydrate you, caffeine operates as a diuretic, meaning that it can cause you to lose liquid more quickly. A study on rats published in the American Journal of Physiology in 2016 also found that rehydrating with soft drinks can actually make dehydration worse. Stick to electrolyte-rich drinks and plain water if you're feeling very dry-mouthed.


You're Consuming An Imbalanced Amount Of Salt

Sodium is one of those Goldilocks substances: too much and too little can both create difficulties. If you ingest very little salt, your body stops conserving as much water in its organs, leading to a higher rate of dehydration, according to Harvard Health. On the other hand, consuming too much salt can make you urinate more, which can also make you dehydrated.


You've Been Sick

Being sick can make you dehydrated, depending on the kind of illness. For example, you may lose fluids if you have diarrhea. Certain meds can also dehydrate you, Dr. Trentacosta says. "Some medications purposely flush water and electrolytes out of the body," she says. Diuretics, laxatives, antacids, and blood pressure medication can all cause dehydration as a side effect.


You're Not Actually Drinking Enough Water

Even if you're drinking eight glasses a day or more, that may still not be enough for you, depending on your size and level of physical activity. "You may not actually be getting as much water as you think," Dr. Trentacosta says. "The general recommendation is to drink about eight glasses of water a day, but this should be tailored to individual’s weight and activity levels."

If you're experiencing signs of chronic dehydration despite drinking lots of water, talk to your doctor about what might be going on and how to stay hydrated.


Scott Michael Schreiber D.C.

Dr. Natasha Trentacosta M.D.

Studies cited:

Popkin, B. M., D'Anci, K. E., & Rosenberg, I. H. (2010). Water, hydration, and health. Nutrition reviews, 68(8), 439–458.