Dehydration is a common trigger for headaches, affecting approximately one-third of migraine sufferers. When your body lacks sufficient fluids, it can cause your brain to temporarily contract and pull away from the skull, stimulating pain receptors in the meninges (the lining around the brain). This mechanism is believed to be responsible for dehydration-induced headaches. To determine if your headache is caused by dehydration, look for these key signs and symptoms:
Characteristics of a Dehydration Headache
- Pain on both sides of the head
- Throbbing or pulsating head pain
- Pain limited to your head (not affecting neck, back or shoulders)
- Worsening pain with physical activity
Accompanying Dehydration Symptoms
Along with the headache, you may experience:
- Extreme thirst
- Dark-colored urine or reduced urination
- Dry or sticky mouth
- Dizziness or lightheadedness
- Fatigue
- Muscle cramps
- Increased heart rate
- Confusion
Key Indicators
Some telling signs that your headache is likely due to dehydration include:
- Relief after drinking fluids
- Headache occurs along with other dehydration symptoms
- Pain develops after fluid loss (e.g. sweating, exercise, illness)
- Lack of recent fluid intake
Differentiating Factors
Unlike other headache types:
- Dehydration headaches typically don’t cause facial pain or pressure (as sinus headaches do)
- They don’t usually cause neck pain (common in tension headaches)
If you suspect dehydration is causing your headache, try slowly sipping water and resting in a cool, dark place. The headache should improve within a few hours of rehydration. If symptoms persist or worsen despite rehydration, consult a healthcare provider to rule out other underlying causes.
