Dehydration affects nearly every system in the body, and the lungs are no exception. Not taking in enough fluids can impact your ability to breathe deeply and cause significant respiratory distress if you are severely dehydrated.

If you’re healthy, your body should compensate for mild dehydration. However, if you’re dehydrated with chronic medical conditions or are acutely ill, you may notice shortness of breath. Keep reading to find out more about the connections between dehydration and shortness of breath.

Severe dehydration can eventually lead to respiratory distress, but it’s not technically the cause of shortness of breath. Let’s break down what we mean by this. The two main mechanisms that would lead to breathing difficulties when dehydrated would be:

  1. hypotension (low blow pressure)
  2. lactic acidosis (too much acid in the body)

If the dehydration is bad enough to lead to fluid volume loss in the body, this can cause hypotension. If you are hypotensive (from dehydration or otherwise), the hypotension can cause shortness of breath, rapid heart rate, dizziness, confusion, nausea, and other symptoms.

Another condition that dehydration can produce is called lactic acidosis. Excess lactic acid building up in the lungs can cause shortness of breath and other symptoms like rapid breathing or muscle cramps.

So it’s not the dehydration itself that leads to difficulty breathing, but if the dehydration is bad enough to cause another condition it can sometimes lead to shortness of breath. For the most part, your body can adjust to mild dehydration. You may have some smaller changes in lung function, but it won’t usually cause severe shortness of breath.

Smoking and dehydration

Dehydration in the lungs and airways can also increase the thickness of airway mucus. This effect usually occurs when smoking cigarettes, where hot air and cigarette smoke cause airway dehydration. Thicker mucus can make breathing more difficult.

For this reason, healthcare professionals often advocate drinking plenty of water when you’re sick to keep mucus thinner and easier to cough up.

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Related symptoms

Dehydration can occur on a continuum, where you have both early and later symptoms. Treating dehydration as early as possible can prevent unwanted side effects, including shortness of breath, dizziness, chest pain, and even feelings of panic. Here’s how dehydration affects your body:

No DehydrationMild DehydrationSevere Dehydration
pulse rate between 60 and 100 (in most people)rapid pulseweak/absent pulse
eyes don’t appear sunkeneyes appear sunkensunken eyes
normal thirst levelsvery thirsty not able to drink or very weak when drinking

Can dehydration cause shortness of breath in pregnancy?

Shortness of breath is a common pregnancy complication. However, dehydration in pregnancy hasn’t been cited as a common cause of pregnancy-related shortness of breath.

It’s still a good idea to make sure you drink plenty of water while pregnant. If your urine is pale yellow in color, you’re likely hydrating enough.

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The answer to this question depends upon several factors. As a general rule, if you are in good health, drinking water will help you stay hydrated. Staying properly hydrated is one of the best ways to ensure your body is working optimally, your lungs included.

Some medical conditions may impact your body’s ability to tolerate higher levels of water. Examples include congestive heart failure and renal failure. When you have these conditions, your body may not tolerate excessive water intake. In this case, excessive hydration could cause shortness of breath.

While you still need to drink water when you have these conditions, your doctor will direct you on how much you should drink.

If you are severely dehydrated, you’ve lost not only water but also electrolytes. These are substances like sodium, calcium, and magnesium that your body requires to function. If you are moderately to severely dehydrated, drinking water won’t do enough to rehydrate you.

Oral rehydration solutions (ORS) are needed if you are significantly dehydrated. These solutions are sold as a powder you mix or as pre-mixed solutions (Pedialyte is an example). They aren’t quite the same as a sports drink, as manufacturers often add sugars to sports drinks to enhance their taste. The sugar can worsen diarrhea, which isn’t useful if you are rehydrating after a stomach bug.

If you are mildly dehydrated, you can hydrate with fluids such as water, broth, or coconut water (with no sugar added). Some foods like bananas or yogurt can also be good sources of electrolytes.

However, if you are severely dehydrated, you should seek medical attention. Symptoms that may require IV hydration include uncontrolled vomiting, severe fatigue, or coma. You may need intravenous (IV) hydration to help treat your symptoms. This treatment can be done at a hospital, walk-in clinic, or at some commercial IV clinics.

The time it takes to recover from dehydration depends on how dehydrated you are. If you are mildly dehydrated, drinking water or an electrolyte-containing solution could rehydrate you in an hour or less.

If you are severely dehydrated, it may take several hours to rehydrate you. This timeframe is true whether you are rehydrating by drinking or receiving IV hydration. Depending on the cause of your dehydration, you may also experience lingering effects like headaches, muscle soreness, and fatigue for a few days as you recover.

It may be helpful to make a point of drinking extra fluids in the week following a period of severe dehydration.

When should you go to the hospital for dehydration?

Becoming severely dehydrated can cause fatigue and other symptoms that can keep you from getting the help you need. Be sure to let a friend or family member know how you’re feeling so they can assist you if you need it.

You should go to the hospital for dehydration if you experience the following:

  • you can’t drink any fluids or frequently vomit fluids
  • you can’t stop vomiting
  • you feel too tired to drink anything
  • your pulse feels weak
  • you experience numbness or muscle spasms in your face or extremities
  • your mental status drastically changes, such as confusion or fatigue
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Maintaining healthy lungs is one of many good reasons to stay hydrated. If you are very dehydrated, you may notice you have more difficulty breathing.

Seeking immediate medical attention for severe dehydration can enable you to start rehydrating to help your body systems (including your lungs) work properly.