Overview, Causes, & Risk Factors

Dehydration is the condition that results when too much body fluid is lost.

What is going on in the body?

The body is about two-thirds water. When the total water level drops by only a few percent, the person becomes dehydrated. Dehydration results when fluid loss is greater than fluid intake.

What are the causes and risks of the condition?

The causes of dehydration include:

  • not drinking enough water during sports or daily activities
  • vomiting
  • diarrhea
  • excessive sweating, such as from fever or exercise
  • excessive urine output, which can occur with diabetes or the use of diuretic drugs
  • Mild dehydration has few risks, and drinking fluids can easily rehydrate the person. Dehydration is sometimes severe. Serious cases usually occur in infants, sick people, athletes, and the elderly. Unless severe dehydration is treated very quickly, death can result.

    Symptoms & Signs

    What are the signs and symptoms of the condition?

    Dehydration may be mild, moderate, or severe.

  • Mild dehydration can cause light-headedness, a dry mouth, and decreased urination.
  • Moderate dehydration can cause sunken eyes, pale skin, and anxiety.
  • Severe dehydration usually causes a weak, rapid heartbeat and low blood pressure. Severe dehydration can lead to shock and death.
  • Diagnosis & Tests

    How is the condition diagnosed?

    The diagnosis is usually based on the symptoms and a physical exam. When the dehydration is moderate or severe, blood tests are often done. These blood tests give information on imbalances in the blood chemistry. This helps the healthcare provider to figure out the best type of fluid to give through an intravenous or IV to correct the problem.

    Prevention & Expectations

    What can be done to prevent the condition?

    Early intervention is the best prevention. The body needs a constant source of fluids. Eight glasses of fluid a day are recommended to keep the body well hydrated. When a person is ill, especially with diarrhea or vomiting, clear fluids will help keep the body hydrated. Sports safety includes drinking plenty of water during and after exercise to prevent dehydration.

    What are the long-term effects of the condition?

    There are usually no long-term effects with mild to moderate dehydration. Untreated severe dehydration may cause seizures, permanent brain damage, or death.

    What are the risks to others?

    There are no risks to others.

    Treatment & Monitoring

    What are the treatments for the condition?

    The treatment for dehydration is to rehydrate the body. This can be done by drinking fluids or by getting fluids through an IV. Drinking fluids usually relieves mild dehydration quickly. Moderate to severe dehydration may need to be treated with fluids given through an IV.

    What are the side effects of the treatments?

    There are usually no side effects from either drinking fluids or getting them through an IV. If a dehydrated person drinks beverages that contain caffeine, such as teas, soda, and coffee, they may feel worse. Caffeine causes more urination, so it can undo the benefit of drinking fluids. Water, sports drinks, and special beverages for children such as Pedialyte help restore hydration and chemical balance. Pedialyte is sold in pharmacies and many food stores. It is mostly water, but also contains salts to prevent chemical imbalances in the blood.

    What happens after treatment for the condition?

    A person usually will feel much better once his or her body has been rehydrated.

    How is the condition monitored?

    Dehydration is almost always caused by a specific event or disease. So it usually does not need long-term monitoring. A person who tends to take in too little fluid will be encouraged to drink more consistently during the day and during sports.

    Article type: xmedgeneral