Dehydration

Jen Hawkins, MPH

Palo Alto Medical Foundation

Nicole Aguirre - College Writer

Palo Alto Medical Foundation

Dehydration occurs when your body loses more fluid than you've taken in. When you get dehydrated, this means the water in your body has dropped below the level needed for normal body function. Small changes in water levels often go unnoticed and don't cause problems, but losing larger amounts can make you feel sick.

Many people think that dehydration only occurs when doing strenuous exercise or spending a lot of time outdoors on hot day – this isn't true. It's easy, especially if you're drinking a lot of coffee or soda, to forget to drink hydrating drinks such as water or sports drinks. This can cause you to feel tired, dizzy and generally unwell.

What Causes Dehydration?

Dehydration is often caused by gastrointestinal illness, such as vomiting and diarrhea. These illnesses can cause you to lose a lot of liquid quickly, and make it difficult for your body to retain any liquids you take in.

Dieting can drain water reserves as well. Beware of diet plans or supplements, especially laxatives or diuretics. These types of medications cause you to lose excess fluids through your stool or urine. In other words, you're losing "water weight" instead of fat. The results are quick, but this type of weight loss is gained back quickly and can negatively impact your health due to losing fluids and essential nutrients.

It's rare to reach a high level of dehydration while playing sports or exercising because most athletes regularly replace the water they lose from sweating. For example, it's common for an athlete to re-hydrate between quarters or while sitting on the bench. However, if you don't replace the fluids you lose, you can become dehydrated.

Signs of Dehydration

Infrequent urination
Very dark yellow urine
Chapped lips
Dry mouth
Dizziness
Weakness
Lethargy
Thirst
Confusion

Treatment

Mild dehydration can be treated by drinking fluids such as water or a sports drink. If you've been vomiting, try sucking ice chips or having a popsicle after you've stopped vomiting. (At first, ice may be easier to keep down than water.)

More severe dehydration may require intravenous fluids at the hospital. Generally speaking, you should head to the hospital if you feel confused, dizzy, lightheaded or lethargic.

Prevention

The easiest way to prevent dehydration is to drink fluids, especially on hot, dry, windy days. Water is generally the best choice because it's not sugary or caffeinated.

Drink plenty of fluids every day (doctors recommend eight 8-ounce glasses of water daily).
Drink extra water when exercising or participating in other physical activities.
If you play outdoor sports, avoid extremely hot weather.
Eat plenty of fruits and vegetables, which are good sources of water.

Reviewed by: Matthew Ryan, MAed, ATC, PTA

Last reviewed: August 2019