Poor Sleep

Some people who often awaken in the morning with a headache may suffer from the common disorder sleep apnea. In sleep apnea, the person will actually stop breathing repeatedly during the night, causing a poor night's sleep and a headache in the morning. Physicians can diagnose and treat sleep apnea, curing the morning headaches as well.

Tension

Simple stress can lead to tossing and turning, and eventually to a morning headache once the sun starts to rise. Making your bedtime routine extra relaxing, perhaps by taking a hot bath or listening to music, can help you shake the worries of the day and wake up the next day without a morning headache.

Teeth Grinding

Teeth grinding, also known as bruxism, often occurs at night and can be severe enough to cause morning headaches, according to the Mayo Clinic. Bedtime stress relief can help curb bruxism, but a physician may prescribe a mouth guard in severe cases.

Pillow Choice

A wide variety of specialty pillows are available that claim to properly align the head and neck during sleep. However, a 2004 study from Sweden found no difference in headache frequency between regular pillows and specialty pillows. The researchers recommended buying a soft pillow with good neck support.

Cluster Headaches

Most morning headaches are not migraines, but one type of migraine headache--the cluster headache--typically awakens the sufferer in the early morning hours, according to the Cleveland Clinic. Cluster headache causes intense pain, generally focused behind one eye. Physicians can prescribe medication to curb cluster headaches.

Source:

Cleveland Clinic: Headaches

Mayo Clinic: Bruxism

Migraine Headache Center: What Causes Headaches in the Morning

More Information:

Neck Pain and Pillows: A Blinded Study