Twenty-eight million Americans suffer from migraines -debilitating headaches characterized by throbbing pain, usually on one side of the head -and women are three times more likely to be affected by them than men are. The condition is more common than asthma or diabetes, yet more than half of the sufferers have not received a diagnosis. Many do not bother seeing a doctor because they think they have to live with the pain, or they may have been misinformed or misdiagnosed with tension or sinus headaches. That is extremely troubling, because more than half of the sufferers report that their pain is so severe it forces them to stay in bed.

Most of us experience tension headaches, which are characterized by a dull ache on both sides of the head often in the forehead, temples or back of the head. While they are a nuisance, these headaches do not usually interfere with our daily activities. In contrast, migraine headaches can wreak havoc on our lives.

The classic migraine symptom is throbbing pain on one side of the head, often accompanied by nausea, vomiting and hypersensitivity to light and noise. The pain may be aggravated by changing position. But not everyone has the classic symptoms; in fact, migraines can resemble other types of headache. One may experience a stuffy nose, sinus pain and eye tearing as with a sinus headache, or may experience pain in both sides of the head, as is common with a tension headache. A small percentage of patients also experience what is known as an aura, which precedes a migraine attack and usually lasts for less than an hour. Symptoms include visual disturbances, such as light, flashes, zizzag lines or shimmering lights. Others also experience numbness and tingling in their arms and face.

In fact, about 157 million workdays are lost every year due to migraine headaches, according to the National Headache Foundation, in Chicago. Even if the sufferers do receive a diagnosis, they may not get the right treatment. One recent study found that people who have been told they have migraines suffer just as much as those who have not received a diagnosis.

Nevertheless, the good news is that doctors are gaining a better understanding of what causes migraines-and how best to treat and prevent them. What you should keep in mind, however, is that not all painful headaches are migraines. But do not hesitate to call your doctor immediately if you experience a headache along with a stiff neck or fever, or if your headache came on suddenly.