Headache from Dehydration: Signs, Remedies, and Prevention

Inadequate water intake and electrolyte imbalances impact the body’s fluid balance and can cause a drop in blood volume, which often triggers headaches and other symptoms of dehydration.   

Discover how to manage and prevent a headache from dehydration and find out why drinking plain water may not be the best way to stay hydrated.  

What are dehydration headaches?

A dehydration headache, or water deprivation headache, is typically caused by imbalanced fluid levels in the body.

Lack of adequate fluid intake decreases blood volume, which can slow down the transport of oxygen and nutrients to brain tissue and cause a headache. 

Dehydration also impacts vascular tone and can trigger the narrowing of blood vessels linked to various headache disorders, including migraine headache, facial pain, and sinus headache.  

In addition, dehydration is often accompanied by a loss of electrolytes such as potassium, sodium, chloride, and calcium. 

These essential minerals are vital in maintaining the body’s fluid levels, and electrolyte imbalances can exacerbate headache pain and contribute to other dehydration symptoms such as extreme thirst, irregular heartbeat, and fatigue.

Watch the video below to discover seven common causes of headaches. 

Common causes of dehydration headaches

While lack of adequate water intake is the most common cause of dehydration headaches, various other factors can contribute to loss of body fluid and dehydration. 

1. Electrolyte imbalances

Sodium and potassium are crucial electrolytes that facilitate the absorption of water into the body and control the movement of fluids into and out of cells. 

Electrolyte imbalances can cause fluids to simply pass through the digestive tract without being absorbed into the body, explaining why you can be dehydrated despite drinking a lot of water.  

In addition, research published in Frontiers in Nutrition found that potassium regulates muscle and central nervous system functions, and potassium deficiency can lead to blood vessel constrictions linked to migraine attacks.  

2. Alcohol consumption

It’s well known that alcohol dehydrates you, and many people have experienced hangover symptoms, including dehydration headaches. 

Ethanol increases urine production, accelerates water loss, and contributes to electrolyte depletion, which explains why headaches are one of the most common side effects of consuming alcohol. 

3. Excessive sweating 

Fluid loss through sweating is a common cause of dehydration headaches. 

Physical activity, especially in hot and humid climates, can cause dehydration and heat exhaustion, and dehydration headaches are an early warning sign of exercise-related fluid loss. 

In addition, excessive sweating triggers potassium loss, which can exacerbate dehydration and result in more intense dehydration headaches. 

4. Sugar-sweetened drinks 

Relying on sugary drinks such as sodas, soft drinks, and fruit juices to stay hydrated can contribute to chronic dehydration and persistent headaches. 

A study published in the American Journal of Physiology found that sugar-sweetened drinks and beverages containing high fructose corn syrup can change the osmolar pressure within the digestive tract, which draws water into the intestines and contributes to fluid loss. 

“Sugary drinks are some of the worst drinks for hydration and may be responsible for many cases of persistent and unexplained headaches,” explains Dr. Berg. 

Signs you have a headache from dehydration

Dehydration-related headaches typically present with throbbing or dull head pain that most commonly affects the forehead and temples.  

In addition, symptoms such as thirst, dark urine, dry mouth, fatigue, and dizziness are also indicative that your headache may be due to dehydration.

The intensity of dehydration headaches can vary. While mild dehydration may cause slight headaches, severe dehydration can lead to more pronounced and persistent pain.

Most dehydration headaches can be managed at home without the need for medical intervention. However, severe headaches can be a symptom of acute or chronic illnesses, including sinusitis, high blood pressure, and fibromyalgia.

If you have developed signs of severe dehydration or are suffering from persistent headaches, it's crucial to consult a professional healthcare provider for a thorough evaluation of your symptoms.

Because dehydration headaches are caused by fluid loss and electrolyte imbalances, they’re typically diagnosed as secondary headaches, and conventional treatment involves pain relievers, electrolyte replacement therapy, and fluid intake.   

3 dehydration headache remedies

While replacing lost fluids is crucial, drinking water alone will not hydrate you and may not help alleviate dehydration headaches.   

Here are three remedies to get rid of dehydration headaches fast.

1. Replace lost electrolytes 

Drinking water without replenishing electrolytes can worsen electrolyte loss and exacerbate dehydration-related headaches. 

However, it’s best to avoid pre-mixed electrolyte drinks that typically are packed with sugar and caffeine, both of which have dehydrating effects. Instead, use a sugar-free-electrolyte powder that can be mixed with water.

Electrolyte powders with low sodium and high potassium content are among the best products to manage dehydration headaches. 

Excess sodium, especially in combination with low potassium levels, can draw fluids out of cells, leading to brain dehydration and headaches.     

Alternatively, you can make your own electrolyte drink and sip it throughout the day to restore fluids and replace lost electrolytes.

2. Rest in a cool environment 

Resting in a cool place helps reduce body temperature and promotes the dilation of blood vessels, which can help manage symptoms of dehydration headaches. 

3. Avoid dehydrating drinks 

Not all drinks have hydrating effects, and it’s crucial to avoid dehydrating drinks such as alcohol, caffeine-containing beverages, sugary drinks, sodas, fruit juices, and energy drinks. 

Instead, opt for electrolyte-enriched water, herbal teas, lemon water, or unsweetened coconut water to restore fluid levels and relieve headaches. 

Tips for dehydration headache prevention

You can do several things to promote optimal fluid balance and prevent dehydration headaches.

Listen to your body and drink hydrating fluids when you experience thirst to prevent fluid loss and dehydration. 

In addition, it’s crucial to maintain electrolyte balance. While many people obtain plenty of sodium from table salt, research published in Clinical Chemistry found that a large proportion of the population does not consume adequate amounts of potassium, leaving them at risk of electrolyte imbalances.

Incorporating potassium-rich foods and taking an electrolyte powder containing at least 1,000 milligrams of potassium per serving are excellent strategies to promote hydration and prevent dehydration headaches. 

It’s equally important to limit alcohol consumption and avoid excessive caffeine intake from coffee, tea, sports drinks, or energy drinks. Both alcohol and caffeine have diuretic properties that stimulate urine production and fluid loss. 

Sugars and refined carbs have dehydrating effects, which explains why eating sugary foods can make you thirsty. A nutritious low-carb diet like Healthy Keto® can help prevent diet-related fluid loss and lower the risk of dehydration headaches. 

Key takeaways

Headaches are a common symptom of dehydration and are typically linked to inadequate fluid intake and electrolyte imbalances. 

Drinking plenty of fluids, avoiding dehydrating beverages and sugar, and replenishing electrolytes with an electrolyte powder containing at least 1,000 milligrams of potassium per serving promote optimal fluid balance and helps prevent dehydration-related headaches. 

FAQ

1. How do I know if I have a headache from dehydration?

Headaches, in combination with symptoms such as a dry mouth, thirst, dark urine, dizziness, and fatigue, are indicative of dehydration.  

2. How do I get rid of a headache from dehydration?

Replacing lost fluids and replenishing electrolytes helps restore the body’s fluid balance, which can help alleviate a dehydration-related headache.

A sugar-free electrolyte powder formulated with at least 1,000 milligrams of potassium is ideal for rehydrating the body and getting rid of a dehydration headache quickly.      

3. How long does a dehydration headache last?

The duration of a dehydration headache depends on the severity of the dehydration and how quickly lost fluids and electrolytes are replenished. 

Most cases of dehydration headaches improve within a few hours of drinking electrolyte-enriched water, resting in a cool environment, and avoiding dehydrating drinks such as alcohol, sugary drinks, caffeinated beverages, and energy drinks.  

4. Can you feel sick with a dehydration headache?

Yes, it’s not uncommon to feel sick with a dehydration headache. 

Dehydration can cause electrolyte imbalance, which impacts the body’s ability to absorb fluids. This can lead to excessive fluid retention within the gastrointestinal tract, linked to nausea and sickness.   

5. What does a dehydration headache feel like?

Most cases of dehydration headaches feel like a dull, throbbing pain that can affect all parts of the head but often are located around the forehead or temples.

6. How do you get rid of a dehydration headache fast?

The fastest way to improve a dehydration headache is by replenishing fluids and replacing lost electrolytes with a sugar-free electrolyte powder that contains around 1,000 milligrams of potassium.

In addition, it’s crucial to avoid dehydrating drinks such as alcohol, caffeinated beverages, sugary sodas, fruit juices, and pre-mixed sports drinks. 

7. Does drinking water relieve headaches?

Drinking only water may not be enough to relieve headaches. 

Electrolytes play a crucial role in facilitating the movement of fluids into cells, and drinking plain water without electrolytes may not provide headache relief as fluids can’t be adequately absorbed into the body. 

8. Can electrolytes help stop a headache?

Yes, electrolytes can help alleviate headaches.

Electrolytes regulate the body's fluid balance, support blood vessel dilation, and promote a relaxed muscle tone, which helps manage and prevent dehydration-related headaches.  

9. Can dehydration cause daily headaches?

Dehydration can cause blood vessel restriction and slow down the brain’s oxygen and nutrient supply, which is linked to headaches and migraine disorders. 

Inadequate fluid intake, electrolyte imbalances, and consumption of caffeinated beverages, sugary drinks, fruit juices, and sports drinks can lead to dehydration symptoms, including headaches. 

Sources

1. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10540813/ 

2. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6459378/ 

3. https://www.researchgate.net/publication/19333320