There are many different kinds of headaches.
Tension headaches are the most common, accounting for 90 percent of all headaches. It is a constant, mild to moderate intensity of pain, felt in the back of the neck, forehead, temples and scalp, similar to wearing a tight headband.
Cluster headaches are marked by severe pain on one side of the head and a painful, stabbing sensation behind one eye. Smokers are particularly prone to these kind of headaches.
Chronic daily headaches are defined as headaches that occur at least 15 days per month for at least three months. They often start out as tension headaches or migraine and build up to a daily occurrence. Chronic headaches can also result from taking daily forms of medication, including Tylenol, ibuprofen, caffeine and some prescription medications.
Contrary to popular belief, migraines are much more than a very severe headache. The headache is merely a symptom of what can be a disabling neurological disorder for approximately 28 million Americans -- roughly 12 percent of the population. Common migraine affects nine out of 10 sufferers. It consists of a severe, throbbing headache, usually located on one side of the head, along with loss of appetite, nausea, vomiting, and increased sensitivity to light, smells, or noise. The pain worsens with physical exertion. More rare -- just 10-30 percent of attacks -- is a classical migraine, in which the sufferer also experiences so-called "auras": flashing lights, zig-zag lines, distorted vision, or blind spots.
Scientists aren't sure what exactly causes migraine headaches, but research suggests that the attacks are linked to chemical changes in the body that affect blood vessels and certain nerve cells in the head. Blood vessels in the head may first tighten, then expand during a migraine attack, which could explain the aura and throbbing pain. Imaging studies have shown that there is an area in the brainstem at the back of the head that is activated during a migraine attack, which could account for the blurred vision or numbness that some people experience. Migraine may also be due to abnormalities in the serotonin system. Serotonin is a natural chemical in the brain that transmits signals from one brain cell to another.
These changes can be triggered by a combination of many different factors:
- too little (or too much) sleep
- foods such as cheese and alcohol
- missed meals
- extreme emotions
- hormonal factors, such as using a contraceptive pill or having a menstrual period