Your body needs 7 to 8 hours to function normally. So when you get less, it assumes something must be wrong and starts to go into panic mode.

“Your fight-or-flight hormones start to kick in, resulting in an increased heart rate, higher blood pressure, and stress,” says Salvatore Napoli, M.D., of the New England Center of Neurology. And all of those things can contribute to a headache.

An over-the-counter pain med like ibuprofen or naproxen can help you make it through the morning, says Dr. Napoli. They’ll ease the pain by reducing inflammation.

And if you still feel zonked and crappy, take a 20 to 30 minute nap, which will give your body more of the rest it needs to function normally. (Longer naps will probably leave you groggy, making your headache worse.) And get back to a normal sleep cycle so you don’t wake up in pain again tomorrow.

You Got Too Much Sleep

If not enough sleep can trigger a morning headache, spending a whole lot of time under the covers will help it, right?

Not so fast: Snoozing for more than 9 hours at night is associated with a decrease in the brain’s level of the hormone serotonin, Dr. Napoli explains. And low serotonin levels can reduce blood flow to the brain and trigger a headache.

These kinds of headaches often tend to strike on the weekends, when you’re more likely to sleep in—that’s just one reason why you feel lousy when you sleep later than usual. Ibuprofen or naproxen can ease your discomfort, but the best way to keep them from coming back is by getting up after 7 or 8 hours of snooze time, says Dr. Napoli. Setting an alarm on the weekends can help.

Your Endorphins Are Out of Whack

Your body’s production of feel-good endorphin hormones is at its lowest early in the morning. And for some people, that can trigger a migraine.

Low levels of endorphins can affect levels of other neurotransmitters, like serotonin, which cause blood vessels in the brain to narrow, explains Mark Khorsandi, D.O., of the Migraine Relief Center in Dallas and Fort Worth. That narrowing reduces blood flow to the brain, which can trigger head pain.

The bad news is that experts don’t know why this causes headaches in some people and not others. But working out first thing in the morning could be one way to stop the pain, since exercise triggers the release of endorphins, Dr. Khorsandi says.

You Drank Last Night

Duh: Over-indulging on alcohol can lead to a significant headache the next morning. But you don’t have to get wrecked to feel booze’s head-pounding effects.

Even a few drinks can make you dehydrated, which reduced the volume of blood flowing to your brain. And that can make your head hurt, says Dr. Khorsandi. Alcohol can also make it harder to get a good night’s sleep—another common headache trigger.

The best way to start feeling better is to rehydrate, Dr. Khorsandi says. Water or electrolyte drinks (like Gatorade) both work.

Vitamin C tablets or powder stirred into the water can also help your liver process the alcohol more efficiently, getting it out of your system faster, he says.

You Snore

Snoring like a chainsaw can be a sign of sleep apnea, a condition that can cause you to choke, gasp for air, and even temporarily stop breathing throughout the night while you’re asleep.

These choking episodes only last for a few seconds, but they can result in less oxygen getting to your brain, says Dr. Khorsandi.

Experts aren’t totally sure why this might lead to a headache. But some experts theorize that less oxygen could cause blood vessels in the brain to expand, increasing blood flow and pressure in your head that can cause pain.

You can have sleep apnea and not even realize it, especially if you don’t sleep with a partner (who might complain about your snoring).

So talk with your doctor, who’ll recommend further testing if he suspects you have sleep apnea. If you’re diagnosed, a breathing machine worn while sleeping (called continuous positive airway pressure, or CPAP) can manage the condition and get rid of the related headaches.

You’re Late With Your Coffee

Caffeine is a mild drug that stimulates your nervous system. So if you drink coffee regularly and don’t get your fix at the usual time (like if you sleep in, or if you’re trying to quit caffeine), you can feel the head-pounding effects when you wake up.

Caffeine withdrawal abruptly leads to the expansion of blood vessels in your brain. As a result, more blood flows into your brain and exerts more pressure, causing a headache, Dr. Napoli says.

You’re more likely to get a caffeine headache if you’re a heavy coffee drinker or drink your coffee at the same time every morning. If that’s the case, downing a cup is the best way to feel better. And if you’re trying to kick your caffeine habit altogether, cut back slowly—over the course of a week or two—instead of going cold turkey.

You’re Depressed

Depression-related headaches can happen at any time of day. That’s because depression is associated with lower levels of the hormone serotonin.

But they could be particularly likely to strike in the morning. Depression can mess with your usual sleep schedule, and snoozing too much or too little can both trigger headaches, Dr. Napoli says. The pain can also have an impact on your mood, creating a vicious cycle.

OTC pain meds can help in the short term. But the best way to deal is by addressing the root cause of the problem. If you think you might be depressed, talk with your doctor. Antidepressants or therapy can help you get back to normal and solve the problems that are leading to headaches.

 You Have High Blood Pressure

When you have high blood pressure—defined as 140/90 millimeters of mercury (mm Hg) or above—your blood is actually exerting more pressure on your head, Dr. Khorsandi says. And that extra pressure is a common cause of headaches.

Plenty of people who have high blood pressure don’t know it, since the condition doesn’t have many outward symptoms. (Aside from headaches, which you might attribute to something else.)

So see your doctor if your headaches are frequent and unexplainable. If your BP is too high, she’ll recommend lifestyle changes like diet and exercise, or prescribe blood pressure medication.

Bottom Line On Morning Headaches

Often, morning headaches are easy to fix. But in rare instances, they could indicate a serious underlying problem, like a brain tumor or an aneurysm. So talk with your doctor if you’re plagued by headaches frequently (whether they happen in the morning or at other times of the day)—more than twice a week for three to six months, Dr. Napoli says.

You should also see your doctor if your headaches are debilitating or are affecting your life or work. She may perform an MRI or EEG (a test that looks at electrical activity in your brain) to learn more about what’s going on in your brain or prescribe an eye exam, since headaches can be caused by strained vision, too, says Dr. Khorsandi.