Michael John Coleman once had a migraine headache that lasted for 21 days.

"The first five days, you do not sleep," said Coleman, executive director of MAGNUM, a national migraine group. "You become almost in an altered state ... It was a horrifying place to be."

Migraine Quiz | Get Migraines? | Types Of Headache

Migraine sufferers feel a throbbing pain, usually located on one of side of the head, and experience nausea and sensitivity to light and sound. Some also experience visual effects called auras -- light flashes, blind spots or zigzag lines.

According to the National Headache Foundation, migraine headaches affect 29.5 million Americans. Women are almost three times more likely than men to suffer from them.

The disease has an annual impact of more than $24 billion in direct and indirect health care costs, according to research by Thompson Medstat, a health care information company.

Nine out of 10 sufferers said they can't function normally during a migraine, and nearly three in 10 require bed rest, the National Headache Foundation reported. More than 25 percent of sufferers have missed at least one day at work over the last three months due to the condition.

There is no cure, but migraines can be managed with medication and lifestyle changes.

"We don't have a way that people can stop being vulnerable" to migraines, said Kenneth Holroyd, a psychologist at Ohio University. But "there are medications that, taken on a daily basis, can prevent migraines."

Drugs that can prevent migraines include cardiovascular drugs -- such as beta blockers and calcium-channel blockers -- and certain antidepressants, according to the nonprofit Mayo Clinic. Ask your doctor for more information or to get a prescription.

Researchers at New York's Albert Einstein College of Medicine of Yeshiva University have also developed a three-question test to see if your headache is a migraine or not. You can take it online.

The Mayo Clinic also offers a list of symptoms that help define migraines:

Moderate to severe pain. Many migraine headache sufferers feel pain on only one side of their head, while some experience pain on both sides.

Head pain with a pulsating or throbbing quality.

Pain that worsens with physical activity.

Pain that hinders your regular daily activities.

Nausea, with or without vomiting.

Sensitivity to light and sound.

Feel It Coming

You also may have symptoms that can tell you a migraine is about to hit. These can include feelings of intense energy, cravings for sweets, thirst, drowsiness, irritability or depression and excessive yawning.

What causes a migraine is different for many patients, experts said.

Triggers can include hormonal changes, foods, stress, bright lights, intense smells, physical exertion, changes in sleep patterns, changes in the weather or barometric pressure and medications.

Many researchers also believe migraines are inherited.

"You're born with it and it's thrust upon you," said Coleman with MAGNUM, which stands for Migraine Awareness Group: A National Understanding for Migraineurs.

Ohio University's Holroyd said it's important that people seek professional help to get a correct diagnosis if they think they have migraines.

"There are other diseases that can cause headaches, as well," he said, including brain tumors.

According to the Mayo Clinic, there are many different types of treatments for migraines and their symptoms and ways to prevent them. They include:

Pain-relieving medications: These include common products such as ibuprofen and aspirin and other classes of drugs.

Preventive medications: These include cardiovascular drugs, such as beta blockers and calcium-channel blockers, some antidepressants, anti-seizure drugs, cyproheptadine and Botox.

Nausea medications: These include Reglan, Compazine and Phenergan.

Avoid triggers: Avoid certain foods if they have triggered migraines in the past. If a scent is a trigger, try to avoid it. Establish regular sleep patterns and meal times.

Exercise regularly: Regular aerobic exercise reduces tension and can help prevent migraines.

Reduce the effects of estrogen: If you're a woman with migraines and estrogen seems to trigger or make your headaches worse, you may want to avoid or reduce the amount of medications you take that contain estrogen. These medications include birth control pills and hormone replacement therapy.

Quit smoking: If you smoke, talk to your doctor about quitting. Smoking can trigger headaches or make headaches worse.

Holroyd said migraine patients can also keep a headache diary of their pain, the things they may have been doing that triggered the headaches and how long the headaches lasted.

"Triggers seem to be individual for people," he said.