The first thing you should do when you feel a headache coming on is drink some water. Chronic dehydration is an extremely common cause of headaches, which means that it’s not just about how much water you drank today, but about your water consumption habits overall. Being dehydrated can also cause distraction and irritability, which tends to make your symptoms feel worse.
Drinking some water has been shown in studies to relieve dehydration-related headache symptoms within 30 minutes to three hours. If you are prone to headaches, you may be able to decrease their frequency by staying on a good hydration regimen and making sure to eat plenty of water-rich foods like fruits and vegetables.