Dehydration takes place when your body loses more fluid than you drink. Common causes include:

  • excessive sweating
  • vomiting
  • diarrhea

The Mayo Clinic recommends women drink 92 fluid ounces (11.5 cups) per day and men drink 124 fluid ounces (15.5 cups) per day. Individuals on the go, athletes, and people exposed to high temperatures should increase their water intake to avoid dehydration.

When too much water is lost from the body, its organs, cells, and tissues fail to function as they should, which can lead to dangerous complications. If dehydration isn’t corrected immediately, it could cause shock.

Dehydration can be mild or severe. You can usually treat mild dehydration at home. Severe dehydration needs to be treated in a hospital or emergency care setting.

Athletes exposed to direct sun aren’t the only ones at risk for dehydration. In fact, bodybuilders and swimmers are among the athletes who commonly develop the condition, too. Strange as it may seem, it’s possible to sweat in water. Swimmers lose a lot of sweat when swimming.

Some people have a higher risk for developing dehydration than others, including:

  • people working outdoors who are exposed to excessive amounts of heat (for example, welders, landscapers, construction workers, and mechanics)
  • older adults
  • people with chronic conditions
  • athletes (especially runners, cyclists, and soccer players)
  • infants and young children
  • people who reside in high altitudes

Your body regularly loses water through sweating and urination. If the water isn’t replaced, you become dehydrated. Any situation or condition that causes the body to lose more water than usual leads to dehydration.

Sweating

Sweating is part of your body’s natural cooling process. When you become hot, your sweat glands activate to release moisture from your body in an attempt to cool it off. The way this works is by evaporation.

As a drop of sweat evaporates from your skin, it takes a small amount of heat with it. The more sweat you produce, the more evaporation there is, and the more you’re cooled off. Sweating also hydrates your skin and maintains the balance of electrolytes in your body.

The fluid you sweat comprises mainly salt and water. Excessive sweating can cause dehydration since you lose a large amount of water. The technical term for excessive sweating is hyperhidrosis.

Illness

Illnesses that cause continuous vomiting or diarrhea can result in dehydration. This is because vomiting and diarrhea can cause too much water to be expelled from your body.

Important electrolytes are also lost through these processes. Electrolytes are minerals used by the body to control the muscles, blood chemistry, and organ processes. These electrolytes are found in blood, urine, and other fluids in the body.

Vomiting or diarrhea can impair these functions and cause severe complications, such as stroke and coma.

Fever

If you have a fever, your body loses fluid through your skin’s surface in an attempt to lower your temperature. Often, fever can cause you to sweat so much that if you don’t drink to replenish, you could end up dehydrated.

Urination

Urination is the body’s normal way to release toxins from your body. Some conditions can cause chemical imbalances, which can increase your urine output. If you don’t replace the fluid lost through excessive urination, you risk developing dehydration.

The symptoms of dehydration differ depending on whether the condition is mild or severe. Symptoms of dehydration may begin to appear before total dehydration takes place.

Symptoms of mild to moderate dehydration include:

In addition to the symptoms of mild dehydration, severe dehydration is likely to cause the following:

Severe dehydration is a medical emergency. Get immediate medical help if you’re showing any of these signs and symptoms.

Medical emergency

Children and older adults should receive immediate treatment, even if they’re experiencing symptoms of mild dehydration.

If a person in any age group develops the following symptoms, seek emergency care:

Before beginning any tests, your doctor will go over any symptoms you have to rule out other conditions. After taking your medical history, your doctor will check your vital signs, including your heart rate and blood pressure. Low blood pressure and rapid heart rate can indicate dehydration.

Your doctor may use a blood test to check your level of electrolytes, which can help indicate fluid loss. A blood test can also check your body’s level of creatinine. This helps your doctor determine how well your kidneys are functioning, an indicator of the degree of dehydration.

A urinalysis is an exam that uses a sample of urine to check for the presence of bacteria and electrolyte loss. The color of your urine can also indicate dehydration when combined with other symptoms. Dark urine alone can’t diagnosis dehydration.

Treatments for dehydration include rehydrating methods, electrolyte replacement, and treating diarrhea or vomiting, if needed.

Rehydration

Rehydration by drinking may not be possible for all people, like those who have severe diarrhea or vomiting. In this case, fluids can be given intravenously.

To do this, a small IV tube is inserted in a vein in the arm or hand. It provides a solution that’s often a mix of water and electrolytes.

For those able to drink, drinking water along with an electrolyte-containing rehydration drink, such as a low-sugar sports or electrolyte drink, may be recommended. Children with dehydration are often directed to drink Pedialyte.

Homemade rehydration solution

If an electrolyte drink isn’t available, you can make your own rehydration solution using:

  • 1/2 teaspoon salt
  • 6 teaspoons sugar
  • 1 liter water

Be absolutely certain that you’re using an accurate measurement. Using too much salt or sugar can be dangerous.

Things to avoid

Avoid soda, alcohol, overly sweet drinks, or caffeine. These drinks can worsen dehydration.

Here are some ways to prevent dehydration:

  • If you’re ill, increase your fluid intake, especially if you’re vomiting or having diarrhea. If you can’t keep down liquids, seek medical attention.
  • If you’re going to exercise or play sports, drink water before the activity. At regular intervals during the workout, replace your fluids. Make sure to drink water or electrolytes after exercise, too.
  • Dress cool in hot months, and avoid being out in direct heat if you can avoid it.
  • Even if you aren’t active, drink the recommended amount of fluids.

Dehydration occurs when you’re not getting enough fluids. Whether it’s from exercising, hot weather, or an illness, dehydration can quickly become dangerous — no matter the cause.

You can help prevent dehydration by drinking plenty of water throughout the day and taking electrolytes if you start seeing early signs of fluid loss.