Headaches after waking up from sleep are associated with many factors.
With too little sleep or poor quality sleep, the brain does not get enough rest and the brain nerves remain in a state of tension, so it manifests as a headache and dizziness after waking up from sleep.
High blood pressure, generally due to poor blood pressure control, long-term pressure on blood vessels, morning vasoconstriction of the brain blood volume increased caused by the back of the brain pain.
Sleeping with a cold and flu can also cause a headache upon waking.