URL of this page: https://medlineplus.gov/dehydration.html

Dehydration

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Summary

What is dehydration?

Dehydration is condition caused by the loss of too much fluid from the body. It happens when you are losing more fluids than you are taking in, and your body does not have enough fluids to work properly.

What causes dehydration?

You can become dehydrated because of

Who is at risk for dehydration?

Certain people have a higher risk of dehydration:

  • Older adults. Some people lose their sense of thirst as they age, so they don't drink enough fluids.
  • Infants and young children, who are more likely to have diarrhea or vomiting
  • People with chronic illnesses that cause them to urinate or sweat more often, such as diabetes, cystic fibrosis, or kidney problems
  • People who take medicines that cause them to urinate or sweat more
  • People who exercise or work outdoors during hot weather

What are the symptoms of dehydration?

In adults, the symptoms of dehydration include

  • Feeling very thirsty
  • Dry mouth
  • Urinating and sweating less than usual
  • Dark-colored urine
  • Dry skin
  • Feeling tired
  • Dizziness

In infants and young children, the symptoms of dehydration include

  • Dry mouth and tongue
  • Crying without tears
  • No wet diapers for 3 hours or more
  • A high fever
  • Being unusually sleepy or drowsy
  • Irritability
  • Eyes that look sunken

Dehydration can be mild, or it can be severe enough to be life-threatening. Get medical help right away if the symptoms also include

  • Confusion
  • Fainting
  • Lack of urination
  • Rapid heartbeat
  • Rapid breathing
  • Shock

How is dehydration diagnosed?

To make a diagnosis, your health care provider will

  • Do a physical exam
  • Check your vital signs
  • Ask about your symptoms

You may also have

  • Blood tests to check your electrolyte levels, especially potassium and sodium. Electrolytes are minerals in your body that have an electric charge. They have many important jobs, including helping to keep a balance of fluids in your body.
  • Blood tests to check your kidney function
  • Urine tests to check for dehydration and its cause

What are the treatments for dehydration?

The treatment for dehydration is to replace the fluids and electrolytes that you have lost. For mild cases, you may just need to drink lots of water. If you lost electrolytes, sports drinks may help. There are also oral rehydration solutions for children. You can buy those without a prescription.

Severe cases may be treated with intravenous (IV) fluids with salt in a hospital.

Can dehydration be prevented?

The key to preventing dehydration is making sure that you get enough fluids:

  • Drink enough water every day. Each person's needs can be different, so ask your health care provider how much you should be drinking each day.
  • If you are exercising in the heat and losing a lot of minerals in sweat, sports drinks can be helpful
  • Avoid drinks that have sugar and caffeine
  • Drink extra fluids when the weather is hot or when you are sick

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