headache, dehydration
Headaches are one of the most common causes of pain and missed days of work. But what are the key signs that a headache might be due to dehydration?

There are many different kinds of headaches and 9 out of 10 adults will experience one at some point in their life.

Some of the different kind of headaches, such as dehydration headaches, can be easily treated and avoided. This article explores what a dehydration headache is, what signs indicate a person may have one, and how they might treat or prevent it.

What is a dehydration headache?

A dehydration headache is a secondary headache, caused by not having enough fluid in the body. Dehydration headaches can be relatively mild or severe as a migraine.

The body requires the proper balance of fluid and electrolytes to function properly. Every day, the body loses water through daily activities, such as sweating and urinating.

Most of the time, the amount of fluid lost is easily balanced through drinking or eating fluid-rich foods. However, sometimes the body loses water faster than it can be replenished.

During these times, the body can become dehydrated, which can lead to complications including unpleasant dehydration headaches.

When the body is dehydrated, the brain can temporarily contract or shrink from fluid loss. This mechanism causes the brain to pull away from the skull, causing pain and resulting in a dehydration headache.

Once rehydrated, the brain plumps up and returns to its normal state, relieving the headache.

Symptoms

A dehydration headache can feel like a dull headache or an intense migraine. Pain from a dehydration headache can occur at the front, back, side, or all over the head.

Unlike a sinus headache, a person experiencing a dehydration headache will likely not experience facial pain or pressure. Pain is also unlikely to occur in the back of the neck as it might with a tension headache.

Since dehydration headaches only occur when the body is dehydrated, symptoms of dehydration will occur with the headache. These symptoms include the following:
  • extreme thirst
  • reduced urination
  • dark colored urine
  • confusion
  • dizziness
  • fatigue
  • dry, sticky mouth
  • loss of skin elasticity
  • low blood pressure
  • increased heart rate
Some people may only experience a dehydration headache if they are severely dehydrated. These people may not only have a headache and some of the above symptoms but also experience some further symptoms.

Further symptoms of severe dehydration that people with a dehydration headache may experience, include:
  • lack of sweating
  • sunken eyes
  • fever
  • delirium
  • unconsciousness
  • shriveled skin
Causes

Diarrhoea, fever, and extreme sweating can all be causes of a dehydration headache.


Dehydration headaches only occur when a person is dehydrated. Even mild dehydration can cause a dehydration headache.

Dehydration happens when the body does not get enough water to meet its needs. Most of the time, the amount of liquid going into the body matches the amount of liquid exiting the body. Water exits the body through sweat or urination.

However, certain factors can disrupt this. These factors increase the risk of dehydration and include the following:
  • diarrhea
  • vomiting
  • extreme sweating, either from heavy exercise or heat
  • fever
  • excess urination
Risk factors for dehydration

Anyone can be dehydrated. The chances are that everyone will experience times of at least mild dehydration. However, some individuals are at higher risk for being dehydrated.

People at higher risk of dehydration include:
  • people who live in higher altitudes
  • infants and young children
  • elderly people
  • people with chronic illnesses, such as diabetes and kidney disease
  • people who take medications that increase urine output
  • endurance athletes
  • people who live in hot climates
These groups of people should take special care to stay properly hydrated.

Treating a dehydration headache

To treat a dehydration headache, addressing both the pain and the dehydration is the best approach to get relief.

If a person has a dehydration headache they should do the following:
  • increase fluid intake
  • replace lost electrolytes with a sports drink
  • temporarily decrease physical activity and avoid heat to reduce sweating

Comment: Sports drinks are generally bad news - they often contain high-fructose corn syrup, artificial flavors and food coloring, none of which belong in your body. A better choice might be fresh coconut water as it is one of the highest sources of electrolytes known, and can be used to prevent dehydration from strenuous exercise.


While the above measures may treat the dehydration, it can take a while for a dehydration headache to be totally relieved.

For fast relief, a person may want to take an acetaminophen or ibuprofen for the pain.


Treating severe dehydration

In certain situations, such as a severe episode of vomiting or diarrhea, home remedies may not be enough to avoid severe dehydration.

When severe dehydrations occurs, a person should seek medical care immediately to prevent serious complications, such as:
  • kidney damage
  • seizures
  • shock
Emergency medical professionals can manage severe dehydration with intravenous fluid and salt replacement.

Preventing a dehydration headache

The best way to prevent a dehydration headache is to avoid dehydration. The following steps can be taken to prevent dehydration:
  • Drink enough fluid: Most people need between 4 and 6 cups of water per day, though some individuals may need more or less.
  • Eat fluid-rich foods: Foods, such as cucumbers, other vegetables, and fruits have a high water content.
  • Get enough fluid throughout the day: Spreading out the amount of fluid consumed rather than drinking it all at once helps keep the body hydrated.
  • Hydrate more during exercise or exposure to hot weather: During times of heavy sweating, such as during heavy exercise or exposure to hot weather, water needs increase. Drinking more water during these times will replenish the extra fluids that are lost through sweat.
  • Treat underlying causes of dehydration: Fevers and infections can cause the body to lose more fluid than normal. Addressing the causes of dehydration while increasing fluid intake can help prevent dehydration.
  • Avoid caffeinated beverages and alcohol: Caffeine and alcohol can both increase urine output, leading to a higher risk of dehydration.
  • Reduce strenuous activity during heat or if feeling unwell: Heat and illness can both increase the body's need for fluids. Heavy exercise can cause extra fluid loss through sweat that can be dangerous in these situations.
Following these steps should help prevent dehydration headaches.

If a person experiences more than the occasional dehydration headache, they should consult a doctor to rule out other underlying causes.