Do you wake up with headaches when you sleep on your stomach?
Headaches can be caused by tension in the neck. This limits the amount of rotation for the head and increases stress through the neck when the head is rotated. Stomach sleepers naturally sleep with their head rotated one direction. In this case, the tension that triggers their pain may increase.
What are the alternative positions?
Back sleeping is my first choice followed closely by side sleeping. Back sleepers typically allow for their cervical and lumbar spine to relax throughout the night, but I also find that this is the least common position to sleep in. If you choose the side sleeping option just know that it helps to have a thicker pillow to allow the spine to rest in neutral and a second pillow to hold onto in order to prevent the shoulder from drooping causing neck tension.
So there you have it, the cure for those morning headaches may be something as simple as changing the way you sleep. Give it a shot and let me know how it goes.