Dehydration in Adults

Dehydration in Adults Overview

Dehydration is a condition that occurs when the loss of body fluids, mostly water, exceeds the amount that is taken in. With dehydration, more water is moving out of our cells and bodies than what we take in through drinking.

We lose water every day in the form of water vapor in the breath we exhale and in our excreted sweat, urine, and stool. Along with the water, small amounts of salts are also lost.

When we lose too much water, our bodies may become out of balance or dehydrated. Severe dehydration can lead to death.

Causes of Dehydration in Adults

Many conditions may cause rapid and continued fluid losses and lead to dehydration:

  • Fever, heat exposure, and too much exercise
  • Vomiting, diarrhea, and increased urination due to infection
  • Diseases such as diabetes
  • The inability to seek appropriate water and food (as in the case of a disabled person)
  • An impaired ability to drink (for instance, someone in a coma or on a respirator)
  • No access to safe drinking water
  • Significant injuries to skin, such as burns or mouth sores, or severe skin diseases or infections (water is lost through the damaged skin)

Symptoms of Dehydration in Adults

The signs and symptoms of dehydration range from minor to severe and include:

Urine color may indicate dehydration. If urine is concentrated and deeply yellow or amber, you may be dehydrated.

When to Seek Medical Care

Call your doctor if the dehydrated person experiences any of the following:

  • Increased or constant vomiting for more than a day

  • Fever over 101°F

  • Diarrhea for more than 2 days

  • Weight loss

  • Decreased urine production

  • Confusion

  • Weakness

Take the person to the hospital's emergency department if these situations occur:

  • Fever higher than 103°F

  • Confusion

  • Sluggishness (lethargy)

  • Headache

  • Seizures

  • Difficulty breathing

  • Chest or abdominal pains

  • Fainting

  • No urine in the last 12 hours


Exams and Tests

The doctor may perform a variety of simple tests at the examination or send blood or urine samples to the laboratory. Through tests and examination, the doctor will try to identify the underlying cause or causes that led to the dehydration.

  • Vital signs

    • Fever, increased heart rate, decreased blood pressure, and faster breathing are signs of potential dehydration and other illnesses.

    • Taking the pulse and blood pressure while the person is lying down and then after standing up for 1 and 3 minutes can help determine the degree of dehydration. Normally, when you have been lying down and then stand up, there is a small drop in blood pressure for a few seconds. The heart rate speeds up, and blood pressure goes back to normal. However, when there is not enough fluid in the blood because of dehydration and the heart rate speeds up, not enough blood is getting to the brain. The brain senses this condition, and the heart beats faster. If you are dehydrated, you feel dizzy and faint after standing up.
  • Urinalysis

    • The color and clarity of urine, the urine specific gravity (the mass of urine is compared with that of equal amounts of distilled water), and the presence of ketones (carbon compounds that signify dehydration) in the urine may all help to indicate the degree of dehydration.

    • Increased glucose in the urine may lead to a diagnosis of diabetes or indicate loss of diabetic control and a cause for the dehydration.

    • Excessive protein in the urine may signal kidney problems.

    • Signs of infections or other diseases, such as liver disease, may be found by urine testing.
  • Blood chemistries

    • The amount of salts (sodium and potassium) and sugar, as well as indicators of kidney function (BUN and creatinine), may be important to evaluate the degree of dehydration and possible causes.

    • A complete blood count (CBC) may be ordered if the doctor thinks an underlying infection is causing the dehydration. Other blood tests, such as liver function tests, may be indicated to find causes of the symptoms.

Dehydration in Adults Treatment - Self-Care at Home

Try to get people who are dehydrated (even those who have been vomiting) to take in fluids in the following ways:

  • Sipping small amounts of water

  • Drinking carbohydrate/electrolyte-containing drinks. Good choices are sports drinks such as Gatorade or prepared replacement solutions (Pedialyte is one example)

  • Sucking on popsicles made from juices and sports drinks

  • Sucking on ice chips

  • Sipping through a straw (works well for someone who has had jaw surgery or mouth sores)

Try to cool the person, if there has been heat exposure or if the person has an elevated temperature, in the following ways:

  • Remove any excess clothing and loosen other clothing.

  • Air-conditioned areas are best for helping return body temperatures to normal and break the heat exposure cycle.

  • If air conditioning is not available, increase cooling by evaporation by placing the person near fans or in the shade, if outside. Place a wet towel around the person.

  • If available, use a spray bottle or misters to spray lukewarm water on exposed skin surfaces to help with cooling by evaporation.

  • Avoid exposing skin to excessive cold, such as ice packs or ice water. This can cause the blood vessels in the skin to constrict and will decrease rather than increase heat loss. Exposure to excessive cold can also cause shivering, which will increase body temperature --the opposite effect you're trying to achieve.


Medical Treatment

Treatment in the emergency department focuses first on restoring blood volume and then body fluids, while determining the cause of the dehydration.

If your core body temperature is greater than 104 °F, doctors will cool the entire body. They may promote cooling by evaporation with mists and fans or cooling blankets and baths.

  • Fluid replacement
    • If there is no nausea and vomiting, fluid replacement is begun. You are asked to drink electrolyte/carbohydrate-containing fluids along with water.

    • If there are signs of significant dehydration (elevated resting heart rate, low blood pressure), fluids are generally given through an IV, a tube placed into a vein.
  • Disposition

    • If your condition improves, you may be sent home, preferably in the care of friends or family who can help monitor your condition.

    • If you remain dehydrated, confused, feverish, have persistently abnormal vital signs, or signs of infection, you may need to stay in the hospital for additional treatment.


If fever is a cause of dehydration, the use of acetaminophen (for example, Tylenol) or ibuprofen (for example, Advil) may be used. This can be given by mouth if you are not vomiting or as a rectal suppository if you cannot take anything by mouth.

Next Steps

Call or return to your doctor or the hospital as instructed.


  • Take prescribed medications as directed.

  • Continue to keep yourself well hydrated with plenty of water or sports drinks.

  • Watch for signs of dehydration in yourself and others.


The foremost treatment for dehydration is prevention. Anticipate the need for increased fluid intake.

  • Plan ahead and take extra water to all outdoor events and work where increased sweating, activity, and heat stress will increase fluid losses. Encourage athletes and outdoor workers to replace fluids at a rate that equals the loss.

  • Avoid exercise and exposure during high heat index days. Listen to weather forecasts for high heat stress days, and plan events that must occur outside during times when temperatures are cooler.

  • Ensure that older people and infants and children have adequate drinking water or fluids available and assist them as necessary. Make sure that any incapacitated or impaired person is encouraged to drink and provided with adequate fluids.

  • Avoid alcohol consumption, especially when it is very warm, because alcohol increases water loss and impairs your ability to sense early signs associated with dehydration.

  • Wear light-colored and loose-fitting clothing if you must be outdoors when it is hot outside. Carry a personal fan or mister to cool yourself.

  • Break up your exposure to hot temperatures. Find air-conditioned or shady areas and allow yourself to cool between exposures. Taking someone into a cooled area for even a couple of hours each day will help prevent the cumulative effects of high heat exposure.



When dehydration is treated and the underlying cause identified, you will recover normally.

Dehydration caused by heat exposure, too much exercise, or decreased water intake is generally easy to manage, and outcome is excellent.

WebMD Medical Reference Reviewed by David T. Derrer, MD on October 26, 2015



Author: Joseph A Salomone III, MD, associate professor, Department of Emergency Medicine, Truman Medical Center, University of Missouri at Kansas City School of Medicine.

Editors: Scott H Plantz, MD, FAAEM,  assistant professor, Department of Emergency Medicine, Mount Sinai School of Medicine; Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine; Steven L Bernstein, MD, vice-chair, Academic Affairs, Department of Emergency Medicine, Newark Beth Israel Medical Center, and assistant professor, Department of Emergency Medicine, Mount Sinai School of Medicine.

© 2015 WebMD, LLC. All rights reserved.