Dehydration Headache

A dehydration headache occurs when you're not drinking enough water, making it easy for your body to lack the fluids it needs to function properly. Dehydration headaches are more common than you might think and often develop during hot seasons and after you finish a strenuous workout session. Staying dehydrated is the best way to prevent a dehydration headache but also lower the risk of serious complications like heat exhaustion or kidney damage.

Types of Dehydration Headaches

There are two main types of headaches related to dehydration. The first is a primary headache, which occurs because you don't have enough water in your body. The second type is a secondary headache, which means dehydration worsens your other underlying conditions, which may cause a headache to develop.

Fluid Loss Headache

Fluid loss headaches occur when your body loses more fluids than it takes in. This type of headache is common during intense physical activities or when you're sick. However, you can also lose water in your body because of the following reasons:

• Vomiting
• Diarrhea
• Taking diuretic medications
• Excessive sweating
• Using laxatives
• Fever
  

Inadequate Fluid Intake Headaches

Inadequate fluid intake headaches happen when you don't drink enough water regularly, which can lead to dehydration. Several factors can affect your hydration habits, including:

• Busy lifestyle
• Lack of access to clean drinking water
• Exercising too much
• Feeling too sick to eat or drink
• Forgetting
• Nausea
• Simply not feeling thirsty

Symptoms 

The most common symptom of a dehydration headache is—you guessed it—a headache. But the symptoms that occur alongside a headache depend on how dehydrated you are.

If you are mild to moderately dehydrated, you may experience these symptoms:

• Excessive thirst
• Sticky or dry mouth
• Not peeing as often as you would
• Darker yellow urine color
• Dry skin
• Muscle cramps

Symptoms of a dehydration headache often worsen if you're severely dehydrated. This may cause symptoms like:

• Not urinating at all
• Shriveled or dry skin
• Feeling irritable or confused
• Dizziness
• A rapid heartbeat
• Fast breathing
• Sunken eyes
• Extreme fatigue

Fortunately, drinking more water and staying adequately hydrated can help prevent and treat these symptoms. However, extreme dehydration can be a sign of a medical emergency. If you or a loved one are severely dehydrated, it's important to see a healthcare provider sooner rather than later to avoid the risk of complications and get the appropriate treatment.

What Causes a Dehydration Headache? 

Dehydration can happen for several reasons: not drinking enough water, sweating too much, and vomiting or having diarrhea, among other causes. When your body is dehydrated, it doesn't have enough water to function properly.

The lack of fluid can cause the veins in the covering of your brain (called the dura mater) to stretch. Your brain, blood, and spinal fluid all need to be in balance within the skull. If there's not enough water, this balance becomes disturbed, which can lead to the onset of headache symptoms. But more research is still needed to understand the exact mechanism that causes this imbalance.

Some studies show that people who are dehydrated feel pain more intensely. This is because being dehydrated affects how your nerves and brain respond to pain signals. So, even if you have a headache from something else, like an underlying migraine, being dehydrated might make your headache hurt even more.

Diagnosis

If you're experiencing frequent dehydration headaches, it may help to see a healthcare provider for proper diagnosis and to ensure that your symptoms aren't a sign of something more serious. During your appointment, your healthcare provider will ask questions about your hydration habits and symptoms. They'll also want to rule out other potential causes of head pain.

In addition to taking your medical history, your provider may also order the following diagnostic tests to learn about your health status:

• Blood test: Determines electrolyte levels and kidney function
• Urinalysis (urine test): Checks urine concentration to assess dehydration
• Check vital signs: Assesses blood pressure and heart rate to check for any abnormalities

These tests help healthcare providers confirm dehydration as the cause of the headache and rule out other conditions.

Treatment

The primary goal of treatment for dehydration headaches is to ensure you're drinking enough water. If an underlying health condition is contributing to fluid loss, your healthcare provider will also suggest treatment options for the condition. To stay hydrated, your provider will recommend the following treatments and remedies, based on the severity of your symptoms:

• Drink plenty of water, especially during and after exercise
• Taking fluids via an intravenous (IV) drip
• Using medications that limit vomiting and diarrhea
• Avoiding headache triggers like alcohol or caffeine
• Trying over-the-counter pain medications if water isn't enough to relieve headaches

It's worth noting that if you have heart failure or kidney problems, your provider may give fluid replacements more slowly to prevent additional complications due to your underlying conditions.

How To Prevent Future Dehydration Headaches

While headaches are common and can sometimes come on sporadically, there are several things you can do to prevent a hydration headache from occurring. Consider the following strategies:

• Drink water regularly to stay hydrated
• Eat water-rich foods like fruits (e.g., grapes or watermelon) and vegetables (e.g., cucumber or celery)
• Try sports drinks with electrolytes for high-intensity exercise in hot weather
• Keep a water bottle with you when you're exercising or in a sunny place
• Avoid drinks with caffeine, as they act as diuretics (water pills) and cause fluid loss

Complications

Unfortunately, dehydration can become severe if you don't receive proper treatment and keep yourself hydrated. The two most common complications of a dehydration headache include:

• Heat exhaustion: Occurs when your body gets too hot because you've been in high temperatures for a long time and haven't had enough water to drink. When you sweat a lot, your body loses too much water, salt, and electroylytes, which can make it hard for your body to cool down and increase your risk of heat exhaustion. Symptoms of heat exhaustion include headache, nausea, excessive sweating, high body temperature, and weakness.
• Kidney damage: When your body doesn't have enough fluid, it makes it difficult for your kidneys to remove waste and toxins. As a result, the toxins in your body can build up and cause damage to your kidneys. Dehydration can also contribute to the formation of urinary tract infections (UTIs) and kidney stones, both of which can lead to kidney damage if not treated promptly.
  

A Quick Review

Dehydration headaches are headaches that develop because you're dehydrated—or, not drinking enough water that your body needs to sustain itself. Symptoms can vary depending on your hydration level, but a dehydration headache commonly causes darker urine color, dry mouth, and muscle cramps. Fortunately, drinking water regularly and keeping fluids on hand when you're exercising or outside can help treat and prevent dehydration headaches.