Recognizing dehydration symptoms early can prevent severe complications like kidney failure or brain damage.

Your symptoms can vary depending on the severity of dehydration, from thirst and fatigue to confusion and no urination.

Severe dehydration may require IV fluids at a hospital to restore your hydration levels.

Symptoms of dehydration include thirst, fatigue, and dry skin. Recognizing these signs can help you prevent serious complications.

Anyone can become dehydrated. Dehydration is more likely among older adults, people who work or exercise in the heat, and those who have conditions or take medications that cause more sweat or urination.

When you're dehydrated, the symptoms you have match the level of dehydration.

Common symptoms of dehydration include:

Signs you are mildly to moderately dehydrated include: 

Thirst

Fatigue

Dry mouth or tongue

Decreased urine output or darker yellow urine

Dry skin

Headache

Lightheadedness, dizziness, or fainting

Inability to focus

Muscle weakness or cramps

Increased heart rate

Quickened breathing

Many people don't recognize less common symptoms, like trouble focusing or muscle weakness, as signs of dehydration. They might not increase their fluid intake.

Fast breathing is another symptom people don't usually associate with dehydration. It can also worsen dehydration since respiration is one way your body loses water. 

Recognizing all dehydration symptoms is crucial, especially if you're at higher risk. As soon as you notice signs, start drinking fluids. This is often all you need for non-severe dehydration.

Symptoms of severe dehydration may include:

Slow capillary refill is another sign of severe dehydration. Press the tips of your fingers or toes: If the color is slow to return, it may be a sign of decreased blood flow. This can be a sign of shock, or when your body doesn't get enough blood flow.

If your internal organs are not receiving adequate blood flow, you may have complications like liver injuries, kidney failure, or electrolyte imbalances.

If you or a loved one has any sign or symptom of severe dehydration, seek medical help.

Infants and young children can become dehydrated more quickly. They vomit and have diarrhea more often.

Since infants and very young children can't express their thirst, look for these signs of dehydration:

No wet diaper for over three hours

Unusual sleepiness

No tears when crying

Sunken eyes

High fever

Irritability

Increased heart rate

Quickened breathing

Sunken soft spots on the baby's head

Call for medical help right away if you or someone you're with has any of these symptoms:

Confusion

Fainting

No urination

Fast heart rate

Fast breathing

Get immediate medical help if you or a loved one has signs of shock, such as:

Low blood pressure

Loss of consciousness

Cold, clammy extremities

Pale or bluish skin and nails

Someone who is severely dehydrated may need intravenous (IV) fluids at a hospital to get hydrated and prevent serious complications. Without treatment, severe dehydration can lead to permanent brain damage, seizures, or death.

Frequently Asked Questions

Can dehydration hospitalize you?

If dehydration progresses far enough, you may need medical help. You may need to stay in the hospital for a day or so as they stabilize you and get your fluids and electrolytes back to safe levels.

How does the ER rehydrate you?

For adults, the ER staff will treat your dehydration by quickly replacing your fluids through an IV (intravenous line). They will also figure out what's causing your dehydration and address that if needed.

For children, the rate of fluid replacement is based on how severe the dehydration is and how much the child weighs.

How do I know if I need IV fluids?

You may need IV fluids with salt at a hospital if you have severe dehydration. A doctor will determine whether you need this level of treatment. 

What happens when you are dangerously dehydrated?

If you have symptoms of severe dehydration, you should seek immediate medical help. You may not get enough blood flow throughout your body. This can lead to serious complications, such as seizure.