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The Dangers of Dehydration

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You’re enjoying the weather and spending a lot of time outdoors, perhaps even being active and breaking a sweat. That’s great, but if you forget to drink water and keep up with your fluid intake to replace lost fluids, you could end up becoming dehydrated. 

Dehydration is a condition caused by the loss of fluid in the body. Meaning, there is not enough fluid, specifically water, in the blood vessels and cells of your body. Losing as little as 1.5% of body water can cause symptoms of dehydration. If you have mild dehydration, you could end up experiencing symptoms such as a slight headache or listlessness. However, if you are severely dehydrated, it could contribute to a potentially life-threatening condition like hyperthermia (heatstroke), a medical emergency.

Please continue reading to learn more about dehydration, including what causes it, how to recognize it, and what you can do to prevent it.

What causes severe dehydration?

The most common cause of dehydration is not drinking enough fluids. This can happen because you’re busy or don’t have access to clean drinking water (for example, traveling overseas or camping). Other reasons for dehydration include:

Diarrhea, Vomiting, Fever

When you have severe diarrhea that comes on suddenly, your body loses a very large amount of water and electrolytes very rapidly. If you have a gastrointestinal illness that causes vomiting and diarrhea together, you can lose even more fluid. Fever also causes fluid loss. The higher the fever, the more dehydrated the body becomes.

Excessive sweating

If you are doing vigorous exercise, it is important to keep track of how much fluid you are drinking to replace fluids. Failure to do so can lead to dehydration. Also, keep in mind that you sweat more and lose more fluid in hot, humid weather. 

Increased urination

In some people with untreated diabetes or those taking certain medications like diuretics (water pills) for high blood pressure, dehydration can develop due to increased urination. 

Who is at risk of dehydration?

People of all ages can develop dehydration. However, infants, young children, and older adults are at high risk of becoming dehydrated. Also, people with specific diseases such as kidney disease or untreated diabetes can lose water due to increased urination. When you are sick with something as simple as the flu, you can become dehydrated because you don’t feel like eating or drinking anything. 

Dehydration occurs more frequently and quickly in people who work or exercise outdoors in humid and hot weather. Such individuals experience excessive sweating, but the sweat evaporates slower than usual, which raises the body temperature, increasing the need for fluids.

What are the symptoms of severe dehydration?

Thirst is a key indicator that the body needs water. However, it is not always a reliable sign of dehydration. Meaning, you might not feel thirsty until you already have mild to moderate dehydration. That’s why it’s important to drink plenty of water in extreme heat or when you’re sick.

In infants and young children, the signs of dehydration can include irritability, listlessness, dry mouth, no urination for several hours, no tears while crying, sunken eyes and cheeks, and a sunken soft spot on the skull.

Older children and adults with dehydration often experience extreme thirst. Other symptoms of dehydration can include dark-colored urine, reduced urine output, dizziness, confusion, tiredness, muscle cramps, and rapid pulse.

You should call your doctor if you have had severe diarrhea for more than 24 hours, you can’t keep fluids down, you are sleepy or irritable, or you have black or bloody stools. Your doctor can provide medical advice on how to treat dehydration. You may need to take an oral rehydration solution to replace lost fluids and electrolytes. In people with severe dehydration, intravenous fluids may be required to rehydrate the body.

Why is dehydration dangerous for our bodies?

Dehydration can cause several serious and potentially life-threatening health complications, including:

Heat injury

This can range from mild heat cramps to more severe heat exhaustion and potentially fatal heatstroke. 

Urinary and kidney problems

Repeated or prolonged dehydration can affect kidney function. It can cause urinary tract infections, kidney stones, and even kidney damage and kidney failure.


Along with fluids, your body loses electrolytes like sodium and potassium when you are dehydrated. These elements are important because they carry electrical signals between cells in the human body. When your electrolytes are out of balance, the signals can get mixed up, causing involuntary muscle movements, convulsions, and loss of consciousness.

Hypovolemic shock 

This is a condition in which the volume of blood in the body is reduced. Low blood volume shock is a serious complication of dehydration that can be fatal. When you have low blood volume, it causes low blood pressure down to dangerous levels. This reduces the amount of oxygen available to tissues and organs in the body.

What are the long-term effects of dehydration?

A large percentage of the human body is water (78% in newborn babies, 60% in adult men, and 55% in adult women). Some vital organs like the heart and brains are made up of 73% water. The lungs are over 80% water. The kidneys and muscles are around 79% water, and the skin is 64% water.

Water is critical for many essential processes in the body, such as chemical balance, delivery of oxygen, regulation of body temperature, shock absorption in the brain and spinal cord, saliva formation, digestion, joint lubrication, and bone cushioning.

It is not difficult to see why a lack of water intake or not enough fluids can cause serious health problems. Again, there may not be specific early signs of dehydration. When left untreated, dehydration can cause severe medical complications. 

That’s why it is essential to drink water at regular intervals every day. Also, you should be aware of the signs and symptoms of dehydration. Finally, seek medical attention and urgent care and be treated immediately if you suspect you or a loved one is dehydrated.

How can you prevent dehydration?

The easiest and best way of preventing dehydration is hydration. Meaning, you can avoid dehydration by drinking plenty of fluids. Make sure you drink enough fluid every day, preferably water. Drinking water is best because water has zero calories. Remember that other fluids like sodas can make you urinate more because they contain caffeine, therefore, making dehydration worse. 

Your water intake should be sufficient that you don’t feel thirsty. Drinking fluids like fruit juice and eating foods with a high water content (fruits and vegetables) can also help to prevent dehydration. 

Remember that your fluid intake needs to be more if you are sick with vomiting or diarrhea, doing strenuous exercise, and when the weather is hot and humid. You should also drink plenty of water in cold weather because dry air can lead to moisture loss. 


  1. https://www.mayoclinic.org/diseases-conditions/dehydration/symptoms-causes/syc-20354086
  2. https://my.clevelandclinic.org/health/treatments/9013-dehydration