Our bodies are made up of 60 percent water (which helps us regulate our body temperature and carry oxygen and nutrients to our cells), so it stands to reason that when we don’t drink enough of it, we don’t feel great. Apart from thirst, a lack of H2O may cause lightheadedness, dry mouth, or even headaches and pains. But can dehydration cause the chest pain you’re feeling every now and then?
Experts in This Article
family medicine physician at Texas Health Harris Methodist Hospital Alliance
medical director of emergency services at MemorialCare Saddleback Medical Center
Chest pain is not a typical symptom of mild dehydration (it’s more often due to things like indigestion or anxiety). But severe dehydration can throw off your blood pressure, possibly resulting in that unpleasant feeling in your chest.
Fortunately, there are ways to prevent severe dehydration and the symptoms that come with it. Learn how to do that here, plus the reasons why chest pain and dehydration are related.
Why does dehydration cause chest pain?
Severe dehydration causes chest pain because of the blood pressure changes that happen when your body doesn’t have enough fluids.
When you’re very dehydrated, your blood pressure drops and less fresh blood, oxygen, and nutrients are transported to your organs. In response, your body tries to raise your blood pressure by increasing your heart rate and constricting your blood vessels.
“This increased heart rate might feel like heart palpitations or even chest pain for some people,” says Marc Taub, MD, medical director of emergency services at MemorialCare Saddleback Medical Center in Laguna Hills, California.
The worse your dehydration is, the more likely you are to feel these effects. In some cases, the cardiac effects of dehydration, like chest pain or rapid heartbeat, could be a sign of an underlying heart issue that’s gone unaddressed.
“Dehydration can almost be looked at as a mini stress test. Feeling chest pain in this setting could be an indicator of an underlying cardiovascular issue,” says Eric Hames, MD, a family medicine physician at Texas Health Harris Methodist Hospital Alliance in Fort Worth, Texas.
In either case, dehydration that’s reached the point of making your chest hurt calls for medical attention.
“Any situation in which a person has chest pain, regardless of the context, should always be considered serious and discussed with a doctor,” says Dr. Hames. Your doctor may run blood work, or tests like an ECG and echocardiogram, to rule out a heart condition.
“Dehydration can almost be looked at as a mini stress test. Feeling chest pain could be an indicator of a cardiovascular issue.”—Eric Hames, MD, family medicine physician
Other side effects of dehydration
Your body has many other ways of letting you know you need to drink more water. “Thirst is probably the best indicator that our body needs fluids,” says Dr. Hames. Other clues that you could be dehydrated include the following, per the National Library of Medicine (NLM):
- Dry mouth
- Dark colored urine
- Urinating or sweating less than usual
- Dry skin
- Fatigue
- Dizziness
As dehydration gets worse, so will the symptoms. Signs of dangerous dehydration include the following, per the NLM:
- Confusion
- Fainting
- Lack of urination
- Rapid heart rate
- Rapid breathing
- Shock
If you start to feel any of those symptoms, call your doctor and go to the nearest ER as soon as possible.
How to treat and prevent dehydration
The best way to treat and prevent dehydration? Drinking enough water, says Dr. Hames. Your exact hydration needs will depend on factors like your age, size, activity level, and climate. Though according to the Mayo Clinic, you should roughly aim for anywhere between 9 and 12 cups of water (or other hydrating fluids) per day.
If you’re more physically active or are sweatier than usual (from hot weather or illness), Dr. Taub recommends bumping up your fluid intake. You’ll know you’re getting enough water if your urine is the color of straw or lemonade, per the Mayo Clinic. If it starts to look more like apple juice, you’re dehydrated.
Even if you only feel a little thirsty, start sipping. “Mild dehydration can typically be resolved by drinking more fluids,” and you’ll likely start to perk up within 15 to 20 minutes, says Dr. Hames.
While plain water is always a good choice, you may also want to consider an electrolyte drink—like Pedialyte or Gatorade—if you’ve been sweating heavily, vomiting, or have had diarrhea, adds Dr. Taub.
Treating severe dehydration, however, will require medical attention, because it can lead to kidney damage if left untreated. “Situations of severe dehydration should be treated in a medical setting with aggressive IV fluid rehydration and close monitoring,” says Dr. Hames.
When to see a doctor
While some causes of chest pain are mild and don’t require immediate medical attention (like indigestion or stress, for example), other causes, including severe dehydration, should be treated immediately, say Dr. Hames and Dr. Taub. Chest pain from a lack of water will often come with other symptoms like confusion, dizziness, fainting, or heart palpitations, per the NLM.
In some cases, chest pain could be a sign of another underlying health issue. “Chest pain can happen for many reasons, such as heart attacks, blood clots, pneumonia, or even injuries to the chest,”says Dr. Taub. All of those things require a medical workup. So if the discomfort isn’t easing up, and comes with other concerning symptoms, call 911.
FAQ
How long do dehydration symptoms last?
Dehydration symptoms last until you’ve adequately replenished your fluid stores—i.e., drank enough water. The average recovery time from dehydration, if it’s mild, should be about 15 to 20 minutes after starting to drink, notes Dr. Hames.
What drink will hydrate you the fastest?
Considering your body is around 60 percent water, plain old H2O “is always the best answer when it comes to rehydrating,” says Dr. Hames. But if you’ve been sweating heavily for a sustained period (like if you’re active on a hot day), try an electrolyte drink like Gatorade or Pedialyte. “Electrolyte replacement beverages work great for rehydrating and replenishing fluids and electrolytes,” he adds. With children, however, make sure to avoid sugar-heavy sports drinks since they can lead to diarrhea, according to the Nemours Foundation. You could also try drinking coconut water or eating water-rich fruits like watermelon.
What should I do if I wake up dehydrated?
No need to do anything special. It’s pretty normal to feel thirsty when you wake up (after all, you just went the whole night without drinking anything). Just down a big glass of water before your coffee, or keep your trusty water bottle near your bedside (psst: check out these water bottles with straws if you don’t have one). You should start to feel more hydrated within 15 to 20 minutes.
—reviewed by Jennifer Logan, MD, MPH
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