Do I Have a Dehydration Headache? Signs, Causes, and Treatment

Nine out of every ten people will experience a headache at some point in their lives, and if you’re one of the people in the majority, you undoubtedly know how painful headaches can be. Headaches have many different causes, but no matter why you get a headache, they can stop you in your tracks and disrupt your day. One of the most common causes of headaches is dehydration. Approximately 75 percent of Americans are chronically dehydrated, putting them at increased risk of experiencing symptoms like dehydration headaches. What are the symptoms of dehydration headaches, what causes them, and how can they be treated?

What is dehydration?

Dehydration impacts hundreds of millions of people each day. An estimated 75 percent of Americans are chronically dehydrated, which causes many people to experience unpleasant symptoms, such as dehydration headaches. Dehydration occurs when the body loses more fluid than it takes in. Fluid is usually lost through sweat and urine, but when a person is sick, they also lose fluid from vomiting and diarrhea. There are many factors that contribute to your fluid levels, including the balance of electrolytes in the body. Electrolytes are positively or negatively charged mineral ions that dissolve when exposed to water. Electrolytes have hundreds of different roles in the body, but one of their most important tasks is maintaining the proper balance of fluids in the body. Electrolytes are excreted through sweat, urine, diarrhea, and vomiting, and when we experience an electrolyte imbalance, dehydration is often soon to follow. Dehydration most commonly occurs in warmer climates, with increased physical activity, at high altitudes, and when people are sick, but anyone can experience dehydration if they do not take in the proper amount of fluids. Senior citizens and children are more likely to experience dehydration than other age groups, but anyone can experience dehydration.

What is a dehydration headache?

Dehydration headaches are a type of secondary headache that occur when the body does not have enough fluid. Secondary headaches are those that are caused by a condition other than a headache condition, such as dehydration, stuffy sinuses, illnesses like meningitis, overuse of medication, or a headache that occurs after an injury. Primary headaches are those that are caused by the headache condition itself and do not have another cause, such as migraine headaches, tension headaches, and cluster headaches. Because secondary headaches like dehydration headaches have another cause, they are often preventable.

What causes dehydration headaches?

Dehydration headaches are caused by fluid loss in the brain. When the brain does not have enough fluid, it may temporarily shrink or contract due to fluid loss. As the brain shrinks, it pulls away from the skull, which causes the pain associated with dehydration headaches. The shrinking of the brain is only temporary, so dehydration headaches are resolved once you have rehydrated and provided the brain with the fluids it needs. The pain associated with dehydration headaches typically corresponds with how severely dehydrated a person is, as the pain increases the more that the brain shrinks and pulls away from the skull. However, some people are more prone to dehydration headaches than others. Dehydration headaches often occur alongside other symptoms of dehydration.

What are the signs of a dehydration headache?

Dehydration headaches can be quite varied in their severity, location, and presentation. A dehydration headache may feel like a dull, aching pain or can be extremely intense, feeling more like a migraine. They can range in severity from mild to severe depending on the level of dehydration. Unlike other types of headaches, which typically occur in a specific part of the brain, dehydration headaches can occur in the front, back, or side of the head, or they can be experienced all over the head. Many people experience dehydration headaches as a pulsing ache that occurs on both sides of the head and is aggravated by physical activity. There is usually no facial pain or pressure associated with dehydration headaches, and pain is not usually felt in the back of the neck. Respondents to a survey conducted by a medical journal described dehydration headaches as aching pain in the head that worsens with movement, including moving the head, bending down, or walking around.

Dehydration headaches are also experienced in conjunction with other symptoms of dehydration, since this type of headache only occurs when the body is dehydrated. Other symptoms of dehydration include:

  • Extreme thirst
  • Dark colored urine
  • Dizziness
  • Dry, sticky mouth
  • Low blood pressure
  • Reduced urination
  • Confusion
  • Fatigue
  • Loss of skin elasticity
  • Increased heart rate

Not everyone experiences headaches when they become mildly dehydrated; some people only experience a dehydration headache when their dehydration becomes severe. Other symptoms that are also commonly experienced with severe dehydration include:

  • Lack of sweating
  • Fever
  • Unconsciousness
  • Sunken eyes
  • Delirium
  • Shriveled skin

If left untreated, severe dehydration can result in complications like seizures, coma, and even death. Severe dehydration requires immediate medical attention.

How can dehydration headaches be treated?

As painful as dehydration headaches can be, they are also highly treatable. Most people report experiencing complete relief from their symptoms within 30 minutes to three hours of drinking water. There are several different ways to treat a dehydration headache once one has occurred.

Drink water

The first step to treating a dehydration headache is to consume water as quickly as possible. Avoid chugging a bunch of water, as this can cause vomiting in some people and also can trigger your kidneys to release more fluid through the urine. Instead, drink one to two glasses slowly while taking steady sips. If you are severely dehydrated, you will likely need to drink several glasses of water steadily over a period of several hours, or may need medical attention in the form of intravenous fluids. 

Electrolyte supplements

Drinking water is an important step in the treatment of dehydration headaches, but you may also need to rebalance your electrolytes in order to restore proper hydration. The body requires sufficient quantities of electrolytes in order to maintain the balance of fluids in the body, and dehydration can disrupt this balance. When looking for electrolyte supplements, steer clear of drinks or supplements that contain caffeine, as this can cause dehydration. Added sugars, carbohydrates, and calories should also be avoided, as well as artificial colors and flavors. Instead, look for an electrolyte supplement that contains sodium, potassium, and magnesium from natural sources and clearly identifies all of the ingredients by name.

Over the counter medications

Most dehydration headaches will improve quickly with water and electrolytes, but some people may find that the pain continues to linger. Over the counter pain medications, such as acetaminophen (Tylenol) and ibuprofen (Advil), can help reduce your pain, provided that you have also taken the steps to rehydrate properly. Avoid taking medications that are intended for the treatment of migraine headaches, as these often contain caffeine, which is a diuretic that can make dehydration worse.

Cold compress

Lying in a cool, dark room with a cold compress on your forehead is another option for treating stubborn dehydration headaches. Placing crushed ice cubes in a ziploc bag is an effective home remedy cold compress that should stay put on your forehead. Other options for homemade cold compresses include wetting a washcloth and placing it in the freezer for a bit so that it gets very cold. Make sure that the room is dark and quiet to avoid any other irritation that could cause your headache to worsen.

How can dehydration headaches be prevented?

The best way to prevent dehydration headaches is to stay hydrated throughout the day. Many people think that chugging a bunch of water a few times a day is enough to prevent dehydration, but in reality, drinking small sips of water frequently throughout the day is more effective. The key to preventing dehydration is consistency and access. Make sure to carry a reusable water bottle with you throughout the day so that you have access to water wherever you are. If you don’t like the taste of water, look for sugar-free drink mixes that can improve the taste of your water without adding calories. When working out, make sure that you have quick access to water and are taking in water throughout the workout. Additionally, taking electrolyte capsules or using electrolyte concentrates in your water can help prevent electrolyte imbalances that contribute to dehydration. The amount of fluids you will need to consume throughout the day in order to stay hydrated vary depending on your environment, how much you sweat, and a number of other factors, so make sure you are paying attention to your specific needs, and start drinking before you get thirsty.