Successful treatment of morning headaches depends on what's causing them.

When a headache strikes during the day, the cause could be something obvious like work stress or a skipped meal. But what makes you wake up with a pounding head?

Morning is actually the most common time to get a headache. Migraine, tension, and cluster headaches are all early risers. They can either wake you out of a sound sleep or start as soon as you get up.

An over-the-counter pain reliever may be enough to calm the occasional morning headache. If morning pain becomes a frequent event, your doctor or a headache specialist can pinpoint the problem and help you find a solution.

The following focus on morning headaches can help you understand:

• Types of headaches that are most common
• What might cause them
• What you can do to help find relief

Three types of headaches commonly strike in the morning -- tension, migraine, and cluster:

• Tension headaches are the most common type of headache. Unlike migraines, they cause an ache rather than a throbbing pain. They often hit in the morning, especially if you get them every day.
• Migraine is an intense, throbbing headache that causes symptoms like nausea, vomiting, and sensitivity to light and sound. About half of migraine headaches start between the hours of 4 and 9 a.m. People with chronic migraine get these headaches 15 or more times a month.
• Cluster headaches get their name from the way the headaches come in clusters or groups. During one of these clusters, you'll get headaches every day at around the same time. For some people, cluster headaches come in the morning. Their early arrival has earned them the nickname "alarm clock headaches."

Cluster headaches are intensely painful. They cause a burning or piercing sensation, often on one side of the head. The pain lasts for a few minutes to several hours. You may also have symptoms like tearing and redness in your eye, a stuffed nose, and drooping of the eyelid on the affected side.

Each cluster lasts for a few weeks or months. After a cluster passes, you can go months or years without another cluster attack.

Here are a few reasons why you get headaches in the morning:

1. You're low on painkillers. Between 4 and 8 a.m., your body makes less endorphins and other natural pain-reducing chemicals. Also, by morning, any pain pills you took before bed have worn off.
2. You snore. Snoring can be a sign of sleep apnea. During sleep, in people who have sleep apnea, the muscles in your throat relax and block your airway. Then you can't get enough oxygen into your lungs. This can raise the carbon dioxide levels in your blood and increase the pressure in your head. Both of these can set off headaches. Snoring itself can also cause morning headaches.
3. You don't sleep enough. Headaches are up to eight times more common in people with sleep disorders, including sleep apnea and chronic insomnia, than in the rest of the population. Just the stress of being tired can cause headaches.
4. You've taken too many pain relievers. Long-term use of pain medicine to treat your headaches can sometimes lead to more headaches. These rebound headaches often strike in the morning hours.
5. You grind your teeth. You may not realize that you clench your teeth while you sleep. Grinding creates tension in the muscles of your jaw and face. This tension can trigger a headache.
6. You've got the wrong pillow. A pillow that doesn't properly support your head puts too much pressure on your neck and shoulders. Muscle tension in those areas can lead to a headache.
7. Your blood sugar dips overnight. Hours after your last meal, your blood sugar level can drop. Headache is one sign of low blood sugar, along with dizziness and nausea.

A morning headache from time to time probably isn't reason to worry. But see your doctor if:

• You get morning headaches several times a week
• They're really painful
• You have other symptoms like snoring or dizziness with them

Which treatment your doctor recommends depends on the cause of your headaches. You may need medicines to prevent migraines and cluster headaches. You can also take a pain reliever first thing in the morning to stop a headache that has already started.

Sleep apnea treatment includes a CPAP machine that pushes air into your lungs while you sleep. Other sleep apnea devices keep your throat open to help you breathe.

If you grind your teeth while you sleep, ask your doctor whether you should wear a mouth guard to prevent you from clenching. Also, try meditation or other relaxation techniques. Daytime stress can contribute to nighttime grinding.

Use pain relievers sparingly and only when you need them. Overuse of these medicines can lead to rebound morning headaches.

To sleep longer, get into a routine. Go to bed at the same time each night and wake up at the same time each morning. Avoid alcohol and caffeine around bedtime because they can keep you awake.