(NewsUSA) - Whether you are at work, at school or planning a day of leisurely activities, a headache can stop you in your tracks. More than 45 million Americans suffer from headaches that disrupt their daily routine.

Medical professionals recognize headaches as a legitimate neurobiological disease. Science, too, is rapidly progressing to better understand what causes headaches.

"Headache pain is a real and legitimate condition," said Dr. Seymour Diamond, executive chairman of the National Headache Foundation and director and founder of the Diamond Headache Clinic.

"Because headaches can interfere with having a good quality of life, frequent headache sufferers should see a health care provider for proper diagnosis and a treatment plan specific to their needs."

Headaches can be classified into two main categories: primary and secondary. Primary headaches include the most common form of headache, known as tension-type headaches. About 78 percent of adults experience tension-type headaches at some point in their lives.

Causes may be related to chemical or neuronal imbalances in the brain or muscle tightening behind the neck or on the scalp. The pain is pressing or tightening, of mild to moderate intensity, and occurs on both sides of the head.

Another type of primary headache, migraine, affects 29.5 million Americans. Migraines are characterized by throbbing pain on one side of the head and are often accompanied by nausea and light sensitivity. Triggers may be individual or a combination of diet, activity, environment, emotions, medications or hormones. Migraines can last anywhere from four to 72 hours.

Unlike primary headaches, secondary headaches are caused by another disease or condition such as aneurysm or meningitis. These headaches can be life-threatening, so immediate evaluation by a doctor is recommended.

For most primary headache sufferers, there are basic, practical steps that can be taken to help enhance quality of life. The National Headache Foundation offers the following tips for headache sufferers:

* Eat regular meals, avoiding food and drinks that are known to trigger headaches, such as aged cheeses, red wine, lunch meats, hot dogs or foods containing monosodium glutamate.

* Maintain a regular sleeping schedule, even on weekends and during vacations.

* Implement daily stress-reduction techniques into your life.

* Keep a "headache diary" of when headaches occur, along with any triggers, to share with a health care provider.

* Make an appointment with a health care provider to discuss symptoms.

* Participate in treatment; be an advocate for your headache care.