Warning Signs of Dehydration and When to Go to the Hospital

While most people are familiar with the basics of dehydration, it goes beyond feeling a little parched. Allison Cadden, PA-C, UnityPoint Health, explains the range of reasons for dehydration, from everyday viral illnesses to less obvious causes, such as certain medications and even injuries. Learn the key factors that leave you thirsty and how to stay hydrated.

Causes of Dehydration

Dehydration happens when your body loses more fluid than it takes in. While not drinking enough water is a well-known cause, dehydration in adults also stems from infectious diseases like the flu, norovirus or salmonella, all of which can trigger vomiting or diarrhea.

Here are some other culprits:

Crush injuries from car accidents, etc.
Diabetes
Excessive sweating
Intestinal obstructions
Kidney disease
Medications, particularly diuretics (water pills)
Skin injuries, like burns
Too much alcohol

Effects of Dehydration

Dehydration significantly impacts the body, particularly cardiovascular (heart) function.

Cadden says, “When you're dehydrated, your blood volume decreases and heart rate increases. This creates tachycardia (a rapid heartbeat) and can make you feel lightheaded when you stand.”

In some cases, a rapid heart rate causes chest pain. Additionally, the dizziness felt isn’t the same as vertigo, which involves a spinning sensation and is a separate health issue.

Dehydration also impairs your body's ability to regulate its temperature, causing heat intolerance and increasing your risk of heatstroke. How well your kidneys clear waste from your blood and bodily fluid is also affected. This puts you at higher risk for kidney stones.

How to Tell if You're Dehydrated

Knowing the signs of dehydration helps you recognize when your body needs fluids. Fortunately, your system sends signals to alert you.

One of the most telltale indicators you’re dehydrated is not going to the bathroom as much or having dark colored urine. Other common symptoms include:

Abdominal pain
Confusion
Dizziness when standing up
Headaches
Lethargy and fatigue (feeling easily tired)
Muscle cramping
Nausea
Poor skin elasticity (skin doesn't bounce back quickly when pinched)
Sunken eyes

Dehydration headaches tend to feel like a dull, achy pain that gets worse with head movements.

A white tongue is a sign of dehydration, too, but it’s also a symptom of other things like an infection, inflammation or poor oral hygiene.

One of the most surprising symptoms of dehydration is back pain. The discs between your vertebrae, which act as cushions and shock absorbers, are largely composed of water. When you're dehydrated, your spinal discs lose some of their fluid. This loss of cushioning creates pressure and friction, often resulting in back pain.

Dehydration symptoms tend to be the same in both women and men.

Signs of Dehydration in Kids

For babies and little kids, dehydration is most common when they’re sick. You might notice there are no tears when your child cries, or they aren’t producing wet diapers. Your child’s mouth, tongue and inside of their nose might look and feel dry, too.

Although dehydration sometimes contributes to a fever, it's more common for a fever to cause dehydration. This is particularly true in young children.

What Happens When Your Body is Low on Electrolytes?

Electrolytes are made up of essential minerals in your body — sodium, potassium, chloride, magnesium and calcium. They’re important because they help maintain your nerve and muscle function as well as fluid balance. Electrolytes also regulate blood pressure, transport nutrients to your cells and keep your heart healthy.

When you’re dehydrated, you’re not just losing water. You also lose these important minerals that disrupt the internal balance of electrolytes in your body.

“For example, low sodium can lead to confusion, seizures and even coma in severe cases,” Cadden says. “Low potassium is often linked to muscle cramps, weakness and heart rhythm problems. Similarly, low calcium can cause heart issues and muscle spasms.”

Sodium helps regulate the water levels inside and outside our cells, which is essential for proper cell function and overall fluid balance.

“On the flip side, if your electrolytes are off, it can make you even more dehydrated by changing how thirsty you feel or how your kidneys work,” Cadden says. “So, losing water and losing electrolytes often go together.”

Beyond dehydration, other medical conditions can cause electrolyte imbalances, such as heart disease, kidney disease, diabetes and endocrine disorders.

How to Quickly Cure Dehydration

The fastest way to cure mild to moderate dehydration is with oral rehydration therapy, a solution made up of water, salt and sugar. Your provider can give it to you in a clinic, or you can get it over the counter. However, don’t attempt to make the solution at home.

In severe cases of dehydration, intravenous (IV) fluids are necessary.

Best Drinks for Dehydration

Knowing what to drink when you’re dehydrated is important for a quick recovery.

“While water is a good choice for mild dehydration, Pedialyte and sports drinks, like Gatorade, are the best for hydration because of their ability to replace electrolytes,” Cadden says. “However, Pedialyte is preferred, because it has more potassium.”

If you don’t have either on hand, try broth or low-fat milk. The salt in broth can replace sodium lost from dehydration, while milk contains electrolytes and carbohydrates that help with rehydration.

“Try not to chug your drink,” Cadden adds. “Instead, slip it slowly, especially if you're feeling sick to your stomach. Gulping it down might make you feel worse.”

Worst Drinks for Dehydration

Alcohol: Alcohol is dehydrating because, as a diuretic, it makes you urinate more and causes your body to lose fluids. It’s especially dehydrating to drink alcohol in the sun.
Carbonated Water: Fizzy drinks, such as carbonated water, act the same as regular water for hydration purposes. While they help with mild dehydration, bloating is common.
Coffee: The caffeine in coffee, tea and some sodas also acts as a mild diuretic. While a moderate amount of caffeinated coffee won’t dehydrate you, it shouldn’t be your drink of choice. Due to its minimal caffeine content, decaf coffee is less of a concern for dehydration.
Soda: Like caffeinated coffee, regular soda has caffeine. It won’t dehydrate you, but it’s low on the list of drinks that’ll properly rehydrate you.
Tea: Plain tea, especially black tea, won’t dehydrate you and counts toward your daily fluid intake. However, it doesn’t have the electrolytes your body needs.

Does Salt Dehydrate You?

A little salt helps your body hold onto water but consuming too much sodium draws water out of your cells and makes you dehydrated.

Can Dehydration be Chronic?

Not drinking enough water regularly (6-8 glasses a day is recommended) can lead to chronic dehydration. Additionally, certain medical conditions increase your risk of dehydration, such as uncontrolled or untreated diabetes, kidney disease and malnutrition (not getting proper nutrition).

Some medications for hypertension (high blood pressure) act as diuretics and lead to chronic dehydration, too. Other blood pressure medicines might make you thirsty or disrupt your kidneys, which also results in dehydration.

Cadden says, “When someone is chronically dehydrated, they might experience symptoms like a dry mouth, constant thirst, headache, dry skin, dark urine and have ongoing low blood pressure.”

Find a Doctor