Humans need to drink water to survive. Many of our body's functions would shut down without drinking water, such as urination, bowel movements and temperature regulation. In fact, over 50% of the human body is composed of water.

No matter the temperature outside, you can become dehydrated if you are not drinking enough water. Dehydration is more than just being thirsty and can lead to serious complications if not treated properly.

If you or someone you know is dehydrated, it is important to recognize the symptoms to receive proper care. Here's how to treat dehydration, according to a medical expert.

Dehydration explained

When your body does not have the sufficient amount of fluids (mostly water) it needs to function, you become dehydrated. Dehydration is when you're losing or using more fluids than you are taking in.

The human body loses fluids in many ways, such as sweating, breathing, urination and defecation, as well as through tears and saliva. You become dehydrated when you are not actively and adequately replacing the lost fluids.

Other health conditions, such as diarrhea, vomiting or excessive sweating, can also lead to dehydration.

Anyone can become dehydrated, however, those at higher risk are infants, children and older people. Infants cannot and children often do not communicate when they are thirsty, making them more prone to dehydration. The same goes for older people, especially those who have cognitive issues.

Dehydration can also be worsened by pre-existing conditions that lead to fluid loss, such as diabetes, causing frequent urination.

Dehydration symptoms

Dehydration symptoms vary depending on someone's age, according to the Cleveland Clinic and Mayo Clinic.

In adults, dehydration symptoms can include:

• Extreme thirst
• Less frequent urination
• Dark-colored urine
• Fatigue
• Chills
• Constipation
• Dizziness
• Red (flushed) skin
• Loss of appetite
• Muscle cramps
• Confusion, headache

In infants and children, dehydration symptoms can include:

• Dry tongue, mouth and lips
• No tears when crying
• Sunken eyes, cheeks
• Sunken soft spot on top of infant's head
• Irritability
• Less frequent urination
• Dry skin

How to prevent dehydration

Dehydration should not be taken lightly – the condition is more than just being thirsty. "Dehydration can kill," said Dr. Donald Kirby, director of the Cleveland Clinic's Center for Human Nutrition.

When you are severely dehydrated, you are losing key fluids, electrolytes, salts and vitamins that help you function. If not treated properly, the most severe cases of dehydration can lead to kidney damage, brain damage or death.

To prevent dehydration, it is important to stay hydrated throughout the day, especially if you are outside for prolonged periods or are active.

Some professionals recommend specific amounts of water to drink each day, but this can vary from person to person. A good indicator of hydration level is urine color. If your urine is:

• Light brown, deep yellow: You're dehydrated
• Pale yellow, resembles lemonade: You're hydrated 
• Clear: You're over-hydrated

"If you have a normal GI tract and kidneys, they are much smarter than we are," said Kirby.

There are also other signs to take into account when hydrating. For example, if you are working out and are sweating a lot, it may be time to drink something, said Kirby.

How to treat dehydration

To treat dehydration, you must rehydrate. "When you do urinate, it's not just water that's coming out," said Kirby.

When you become dehydrated, electrolytes, potassium and sodium may also be lost. These are vital to certain body functions and help regulate the amount of fluid in our bodies.

In mild cases, you should opt for oral hydration by drinking water, sports drinks or drinks with electrolytes, said Kirby. In more severe cases, you may need IV hydration.

If someone's dehydration symptoms – such as confusion, weakness or inability to move – are worsening, this is a sign to seek medical attention, said Kirby.

Additionally, dehydration can be related to other conditions, including heatstroke. If someone is showing different symptoms besides the aforementioned, such as increased heart rate or body temperature, that is another indication to call 911, said Kirby.

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