Dehydration means you are losing more fluid than you’re taking in. The body runs out of fluids to perform normal functions, leading to symptoms that can become especially dangerous in children and the elderly.
The most common causes of dehydration are diarrheal illnesses. Diarrheal illnesses in children cause about 220,000 hospitalizations (which is almost 10% of all children who require hospitalization), and 400 deaths per year in the US. The elderly naturally have lower quantities of water in the body and are more likely to limit the consumption of water, or take water pills that increase urination.
While most cases of dehydration are mild and are easily reversed with fluid replacement, some can be severe and life-threatening, requiring treatment at the hospital.
Dehydration symptoms and signs
Dehydration symptoms in adults include:
- Feeling thirsty
- Dry mouth
- Fewer trips to the toilet to urinate and the urine color is darker than normal
- Fatigue and dizziness
- Light-headedness and even fainting, especially when standing up
Severe dehydration also causes increased heart rate, rapid breathing, decreased blood pressure, very little to no urination, and decreased level of consciousness
Infant and young children are unable to tell if they are thirsty, but there are a few signs that suggest dehydration, which may be severe:
- Dry tongue and dry mouth
- Very little or no tears when they cry
- No wet diapers for three or more hours
- More irritable, cranky, and restless
- Sunken fontanelle (soft spot on top of the head)
- Wrinkled skin
It is important to note that babies and young children may be dehydrated without showing obvious signs and symptoms. Parents should monitor if the infants are getting enough fluids by checking the diapers which should get soiled after most feedings or every 2-3 hours.
Complications of dehydration at any age include heat injury (including the life-threatening heat stroke), kidney complications, and seizures. In case of severe dehydration, a person may experience extreme confusion, even develop shock, and may even die without replacing the fluids lost.
Dehydration causes and risk factors
The most common causes of dehydration are diarrheal illnesses.
- Acute, severe diarrhea due to a gut infection (gastroenteritis) is often associated with vomiting as well, causing significant loss of water and electrolytes. Rotaviruses are the most common causes of dehydration and severe diarrhea in infants and young children
- Infections that cause fever also lead to dehydration, and the higher the fever, the more severe is dehydration.
- Increased sweating due to intense exercise or living in hot, humid environments is a common risk factor in athletes, firefighters, and construction workers
- Diseases or drugs that increase urination may also lead to dehydration.
Babies and small children are at increased risk of becoming dehydrated because a greater portion of the body is made of water compared with adults. Their bodies also use more water because they have a high metabolic rate.
Furthermore, their kidneys do not conserve as much water as adult kidneys do. Infants and young children often experience more diarrhea and vomiting if they get an illness and therefore are more likely to become dehydrated. Children tend to drink less water when they get ill.
Older adults are also at risk for dehydration for several reasons. Firstly, they naturally have a lower volume of water in their bodies. They often do not feel thirsty and forget to drink water.
Some limit the amount of water they drink due to kidney diseases or bladder issues like incontinence. Many elderly take water pills (diuretics ) for heart diseases, and these drugs increase their urine output.
People who work or exercise outside are also at higher risk of becoming dehydrated, especially when the air is hot and humid.
Life-threatening causes of dehydration include gut infections (gastroenteritis), burns, heat stroke, a diabetes complication called diabetic ketoacidosis, gastrointestinal obstructions, heat stroke, and excess thyroid hormones in the body.
Most cases of dehydration are mild and can successfully be managed at home with water and electrolyte replacement.
- Infants and children who are dehydrated due to diarrhea, vomiting, or fever need over-the-counter oral rehydration solutions like Pedialyte, Infalyte, and Rehydralyte that provide water and the right balance of electrolytes to manage dehydration. The typical starting dose is one teaspoon every one to five minutes then increases the dose as tolerated.
- Older children and adults can also use water with electrolytes or plain water. Coconut water is another popular drink that offers hydration and some electrolytes. Coconut water contains plenty of water, and is a good source of potassium and glucose, but does not provide enough sodium, chloride, and bicarbonate. Researchers suggest that adding a bit of salt can optimize the electrolyte levels of coconut water and help manage dehydration when oral rehydration solutions are not available.
Apple juice, Ginger ale, milk, and chicken broth should not be used to replace fluids. These drinks have too much sugar and too little sodium, leading to impaired water absorption and worsening the degree of dehydration. If drinking plain water is not appealing, add a slice of lemon, cucumber, or some mint leaves.
Medical treatment should be thought of in severe cases of dehydration, and you or a loved one experience excess irritability or disorientation, are unable to drink water, have diarrhea for more than 24 hours or the stool is black or bloody. Severe dehydration is treated at the emergency level with fluids and electrolytes given intravenously.
The best way to prevent dehydration is to make sure you drink plenty of fluids and consume foods rich in water. Aim for 6-8 glasses of water daily and several servings of vegetables and fruits. Clear, white, or light yellow urine suggests you are well hydrated, while dark-colored urine may be due to dehydration.
Drink more water in case:
- You experience vomiting or diarrhea
- You work or exercise outdoors and the air is hot and humid. Start drinking water 3-4 hours before a workout, drink half a cup every 15 minutes when exercising, and drink more water after a workout.
- You need extra water when the weather is cold and dry, especially at high altitudes.
- If you have an infection, especially when fever and excess sweating are present.
- If you drink alcohol, coffee, and caffeine-based drinks, they also dehydrate you.
Dehydration can be prevented in many cases by drinking enough water and consuming vegetables and fruits. Drink more water if you lose more fluids due to diarrhea, vomiting, excess sweating or if you have an illness.