Early morning hours between 4 and 8 a.m. are when the body's natural painkillers are at their lowest levels, so all types of headaches may be more likely or severe at this time, according to Everyday Health. Sleep apnea, teeth-grinding or other dental problems, depression, or overnight diminished levels of prescribed medications may also cause morning headaches. Migraines are more likely to occur in the morning than at other times, notes Health.
Doctors clinically assess headaches based on multiple criteria, the evaluation of which can lead to the likely cause of the pain, explains Everyday Health. The time of day at which the pain regularly or generally occurs is an important issue, but some other criteria include whether the pain is new or ongoing, the severity of the pain, and the presence of any seemingly related or co-occurring symptoms, such as vision or balance disturbances and weakness, altered sensation or pain in other body parts. Other factors a doctor considers when assessing headaches include where on the head the pain occurs and whether anything increases or decreases the severity of the headache.
Headaches that occur in the morning are only rarely a sign of a serious medical condition, notes Everyday Health. Individuals should seek treatment or evaluation when a change occurs in the usual pattern of headaches in their lives.