14 Signs of Dehydration that May Signal a Migraine Attack, Plus How to Prevent It

It’s not clear why dehydration can lead to migraine for some, though fluid imbalance may activate pain receptors. Hydrating before you feel thirsty, before and after exercise, and in hot environments may help prevent hydration-related migraine.

Staying hydrated isn’t usually a problem for me except when I’m running errands or rushing to meet a deadline.

Before I know it, fatigue and muscle tension set in. Then, my eyelids start to feel heavy.

What I’m describing is my prodrome phase of migraine. This phase can start 1–3 days before the onset of headache symptoms, though everyone’s prodrome phase will likely be different.

Whereas a headache caused by dehydration can go away (eventually) after I drink plenty of water or liquids containing electrolytes, migraine symptoms often persist and worsen depending on how dehydrated I am.

Dehydration occurs when you’re losing more fluids than you’re consuming. Since dehydration can be a migraine trigger, it’s important to recognize and intervene before it’s too late.

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The connection between dehydration and migraine

You can become dehydrated when your body doesn’t have enough fluids to function properly. This means having the right balance of water and electrolytes (like sodium and calcium), which you get from your food and drinks.

According to the American Migraine Foundation, 1 in 3 people with migraine consider dehydration to be a trigger. Even people without chronic migraine can be susceptible to headaches from dehydration.

A small 2020 study suggests that the more water you drink, the lower the severity, duration, and frequency of migraine symptoms, though more research is needed to confirm this.

Moreover, it’s not clear why dehydration triggers migraine. Researchers suspect that it has to do with a fluid imbalance that affects electrical activity (i.e., activates pain receptors) in the brain.

For people with migraine like me, preventing dehydration is important for managing debilitating head and neck pain. If I act quickly to replace electrolytes lost through sweating and urination, there’s a better chance of reducing the severity and duration of my symptoms.

Signs of dehydration that may lead to migraine

You’re more likely to notice being thirsty in warm weather or if you’re working up a sweat. But dehydration is also common during cold and flu season when you’re losing fluids due to a fever or runny nose.

Common signs of dehydration include:

• extreme thirst
• headache
• dry mouth
• dizziness
• confusion
• dark-colored urine
• less urine than usual

Less obvious signs of dehydration include:

• dry skin
• muscle cramps
• fatigue
• bad breath
• chills
• heart palpitations
• food cravings

It’s important to be aware of these signs of dehydration, as they may indicate a migraine is just around the corner.

Causes of dehydration

Any gradual or rapid loss of water and electrolytes can lead to dehydration.

This can include:

• sweating
• urinating
• vomiting
• diarrhea

You tend to sweat more when you’re exercising or working in hot and humid conditions. Excessive sweating can also occur when you have a fever or if you use a spa or sauna.

Having a sore throat can make it painful to swallow. As a result, you’re more likely to avoid eating or drinking even if it can help you recover faster.

If you’re sick with vomiting and diarrhea at the same time, the loss of electrolytes can be more significant. Certain medications and chronic conditions like diabetes can also prompt more frequent urination and fluid loss.

Aside from heat, exposure to dry air in cold climates and high altitudes can put you at risk for dehydration.

Hydration guidelines

You may have heard the advice that drinking eight glasses of water a day is necessary for staying hydrated. However, there isn’t much evidence to support this claim.

Personally, it’s hard to keep an accurate log of how often I refill my water bottle. Plus, the “eight glasses rule” doesn’t take into account the water that comes from the foods I eat.

Water from food accounts for roughly 19% of total fluid intake, according to the National Academy of Sciences (NAS). They suggest that an adequate daily fluid intake for healthy adults ages 19–30 years is 3.7 liters for men and 2.7 liters per day for women. That’s about 16 and 11 cups, respectively.

It’s possible, but rare, to drink too much fluid. This can lead to a dangerous condition called hyponatremia, or low blood sodium.

How to stay hydrated

I focus on these four tips to keep migraine at bay:

1. Keep a water bottle on hand.
2. Rest if you feel hot or dizzy.
3. Try to drink before you get thirsty or engage in heart-pumping exercise.
4. Monitor the color of your urine. Colorless or light-yellow pee is a good sign that you’re drinking enough water.

What to do if you’re dehydrated

If you’re experiencing fever, vomiting, or diarrhea, it’s important to replenish fluids with electrolyte-infused beverages like coconut water or sports drinks. Another critical time to rehydrate is during and after a workout or when you’re exercising outdoors.

If you become severely dehydrated, speak to a doctor or dietitian about your hydration needs and how to rehydrate safely.

Frequently asked questions

What does a dehydration migraine feel like?

Symptoms can vary based on age and the presence of other health conditions. Some people experience nausea and sensitivity to light or sound. Pain may involve pressure or a throbbing sensation on one side of the head.

How long does a dehydration headache last?

A dehydration headache can last between 30 minutes and 3 hours, depending on how quickly you rehydrate. The pain can affect the entire head or be confined to one area like the front or back of the head.

Do electrolyte drinks help migraine?

Preventing dehydration can help reduce the likelihood of experiencing migraine symptoms. Electrolyte solutions like sports drinks can help you rehydrate more quickly than water alone.

Takeaway

Dehydration occurs when your body loses fluids faster than you can replace them. Signs vary from person to person and include headache, dizziness, and dry mouth.

Although dehydration doesn’t cause migraine, it can be a trigger for some people or worsen symptoms during a migraine attack.

Seek medical attention if the pain persists or you become severely dehydrated.