Infinite things can cause headaches, but if you’re waking up with a headache every morning that eventually goes away, we can narrow it down to a few possibilities. Waking up with a headache is a good indication that you slept on your stomach, or you’re unknowingly doing something at night to cause the pain.
Disclaimer: Persistent headaches can be symptoms of something serious. Don’t ever mess with your head. Go see a doctor immediately.
Are you stomach sleeping? Stomach sleeping all night with your head to one side can kink the temporal artery in your neck. If this happens you wake up with a temporal headache. These come and go very quickly and without warning, but are usually worse at one time of the day or night. You feel the pain behind one eye, and sometimes it’s so bad that your eyes water or your nose gets runny. Then suddenly, “poof,” it’s gone.
Are you sleeping on your stomach and even raised a little on a pillow? This can make the nerves on one side of your neck send too many signals to your brain, while the other side goes radio silent. You get a headache that starts back at the base of your skull and shoots up behind your eye, on one side. It’s like a sharp stabbing pain, but not like a migraine where you feel nauseated and can’t stand any light.
Headache from Hypoxia
If you have Obstructive Sleep Apnea (OAS) you might often wake up with a migraine-like headache. With OAS, your airways are blocked while you sleep. (Read more about sleep apnea here.) Hypoxia means you don’t have enough oxygen in your blood supply. This means you aren’t getting enough oxygen to your brain, thus causing a dull ache.
One main cause for teeth grinding at night (sleep bruxism) is an airway problem when you sleep, for instance, with OAS. Or, you could just be stressed out or upset about something. If you sleep on your stomach, you put constant pressure on one side of your face. This pushes your jaw out to the side. You can’t swallow unless your jaw is centered, so, to avoid choking on your saliva, you’ll grind your jaw back to center, and then relax after you swallow, letting it push back out to the side. You swallow hundreds of times in one night. Grinding your teeth back and forth tires your jaw muscles. Those muscles attach to the sides of your head, so you feel a dull ache around your jaw and temples. Plus, you get blunted , sensitive teeth and receding gums.
Eight hours, or a normal night’s sleep, is a long time to go without a glass of water. You sweat when you sleep, too. So by the time you wake up you’re already in a water deficit. A headache is a clear sign of dehydration.
If the first thing you do every morning is drag yourself into the kitchen to get a cup of coffee, your body might be signaling its addiction with a headache. If this is you, see the above section and try drinking a glass of water before you even get out of bed.
The problem with humans is that we’re creatures of habit. If you sleep on your stomach, chances are you have your head turned in the same direction the entire night and you use a pillow. This can cause any number of headaches. Waking up with a headache is not a fun way to start your day. You know my solution: Stop stomach sleeping and get a proper pillow!