Can dehydration cause migraines?

Yes. Dehydration can shrink brain tissue, trigger pain pathways, and lower your pain threshold, making migraines more likely and more severe. Staying hydrated—about 2 liters of water daily—may help prevent attacks and reduce their intensity.

If you live in Houston, you know our heat and humidity can make it easy to break a sweat—and just as easy to get dehydrated. But for people living with migraines, dehydration isn’t just uncomfortable—it can be a major trigger for painful attacks.

Research shows that about one in three migraine sufferers identify dehydration as a factor that sets off their symptoms. The good news? Hydration is one of the easiest migraine triggers to manage.

In this post, we’ll break down why dehydration and migraines are connected, how hydration impacts the severity of attacks, and practical tips for keeping your water intake on track.

Why Dehydration Can Trigger a Migraine

When your body doesn’t have enough fluids, your brain can temporarily contract or shrink slightly. This can cause it to pull away from the skull’s lining, which is filled with pain-sensitive nerves. That physical change can activate the pathways that produce a headache or migraine.

Beyond the mechanics, dehydration also causes changes in electrolyte balance and blood flow, which may make your nervous system more sensitive to pain. In fact, studies show that when you’re dehydrated, your pain threshold drops—meaning your brain is more likely to react strongly to migraine triggers.

What the Research Says

Several studies have looked at hydration’s role in migraine management:

• Fewer and shorter migraines – One study of women with migraines found that those who drank around two liters of water per day had fewer migraine days, shorter attacks, and less disability from migraines.

• Mixed clinical trial results – Some research has shown that increasing water intake by 1.5 liters a day can reduce headache hours and severity, although results vary from person to person.

• Relief during an attack – For those whose migraines are triggered by dehydration, drinking fluids can sometimes provide relief in as little as 30 minutes.

While drinking more water isn’t a cure-all, there’s a clear pattern: staying hydrated may help prevent migraines from starting and reduce their intensity if they do occur.

Why Houston Migraine Sufferers Need to Be Extra Careful

In Houston’s hot, humid climate, it’s easy to lose fluids through sweat without realizing it. Outdoor activities, air-conditioned environments that dry the air, and even salty cuisine can all contribute to dehydration.

Migraine sufferers here may be especially vulnerable during the summer months or after long periods outdoors, so making hydration a daily habit is essential.

IV Hydration for Migraines: What to Know

You may have heard of IV hydration being used for migraine relief in emergency rooms or wellness clinics. While IV fluids can be helpful in certain situations—such as for patients experiencing vomiting or when given alongside migraine medications—they aren’t a guaranteed standalone fix.

Oral hydration (drinking fluids) is generally the first and most effective step for most people. But if you’re unable to keep fluids down during a migraine attack, your care team might recommend IV fluids as part of a broader treatment plan.

Tips for Staying Hydrated and Reducing Migraine Risk

The amount of water you need depends on your body size, activity level, and environment, but a good rule of thumb is around eight 8-ounce glasses (about 2 liters) per day.

Here are some strategies to help:

• Sip throughout the day – Don’t wait until you’re thirsty; thirst is a sign you’re already on your way to dehydration.

• Use reminders – Set alarms or use a water-tracking app to help you stay consistent.

• Eat water-rich foods – Add fruits and vegetables like cucumbers, watermelon, and oranges to your meals.

• Watch your beverage choices – Limit sugary drinks and be cautious with caffeine, which can have a diuretic effect.

• Check your urine color – Pale yellow usually means you’re hydrated; darker shades can indicate dehydration.

When to Seek Help

If you’ve increased your water intake but still find dehydration triggering your migraines—or you’re not sure what’s causing your attacks—it’s time to talk to a migraine specialist. A personalized treatment plan can help identify your specific triggers and give you a strategy for preventing and managing migraines effectively.

The Bottom Line

Dehydration is one of the most preventable migraine triggers, and staying on top of your water intake can make a meaningful difference in your migraine frequency and severity.

At the Migraine Relief Center in Houston, we understand how even small lifestyle changes—like better hydration—can help you take control of your migraines. We work with you to identify your triggers, create a personalized care plan, and provide advanced treatment options when you need them.

Ready to explore a personalized migraine management plan? Contact us today to schedule a consultation.