Headache Facts

Americans spend in excess of $4 billion annually on over-the-counter pain relievers for headache symptoms. Many of these medications fail to provide adequate relief to the headache sufferer. What is a headache, exactly? Are there different types of headaches? What distinguishes different types of headoaches? What can you do to better manage headache suffering? These are all questions we attempt to answer here.

Anatomy of a Headache

Surprisingly enough, the exact mechanism by which headache occurs is not known. There are numerous theories, but no one universally agreed upon cause. What we do know for certain is the basic anatomy of a headache. We know the pain you feel is real and we know the physiology behind the pain.

Headache sufferers may feel as though their brain hurts, but in reality actual brain matter itself is entirely insensitive to pain. Instead, it's the three membranes that cover the brain, called the meninges, that are sensitive to pain.

According to the most widely accepted theory of headache, pain-sensing nerve cells called nociceptors release chemicals called neuropeptides. These neuropeptides cause the vascular smooth muscle surrounding cranial blood vessels to relax, which in turn causes vessel dilation and increased blood flow. Neuropeptides also promote inflammation and tissue swelling. The combination of increased pain sensitivity and tissue and vessel swelling is what causes headache pain. The pain may be confined to one area or it may be generalized and encompass the entire head.

In the final analysis, most headache sufferers don't care about the physiology of pain – they simply want relief. Diagnosing your headache type and identifying those triggers that affect you personally are the keys to alleviating pain.

Headache Classification

In 1988, The International Headache Society (IHS) developed a classification system to assist physicians in the differential diagnosis of headache. This classification system has since become the standard for headache diagnosis and research the world over. The classification criteria, updated in 2004, divide headaches into 14 categories:

  1. Migraine
  2. Tension-type headache
  3. Cluster headaches and other trigeminal autonomic cephalalgias
  4. Other primary headaches
  5. Headache associated with head trauma
  6. Headaches associated with vascular disorders
  7. Headaches associated with nonvascular intracranial disorder
  8. Headache associated with substances or their withdrawal
  9. Headache associated with infection
  10. Headache attributed to disorder of homeostasis
  11. Headache or facial pain attributed to disorder of cranium, neck, eyes, ears, nose, sinuses, teeth, mouth, or other facial or cranial structures
  12. Headache attributed to psychiatric disorder
  13. Cranial neuralgias and central causes of facial pain
  14. Other headaches, cranial neuralgia, central or primary facial pain

So what does all this mean? To your doctor, this classification system means he or she can begin to categorize and treat your headache based on established and proven criteria. To you, the headache sufferer, it means that there are many different types of headaches and diagnosing your particular disorder is the first step to finding relief.

Headaches vary in intensity, frequency and duration and can be triggered by a multitude of physical, emotional, and environmental factors. Establishing the correct diagnosis is critical to developing an effective strategy for managing headache. While the IHS identifies 14 types of headache disorders, most headaches can be classified as either primary or secondary.

Primary headaches are not related to another underlying medical condition. They are headache diseases that are thought to be related to abnormalities of neurotransmitters in the brain. More than 90% of all headaches are considered primary and these include:


Tension-type headache is the most common headache. It typically produces a generalized mild to moderate pain all over the head. It can also cause pain in the back of the neck at the base of the skull. The actual cause of tension-type headaches is still up for debate. Muscle tension was one thought to be the main cause of this particular type of headache pain, but researchers are not convinced it's the only cause, hence the name "tension-type."


Migraine is more common than asthma, diabetes and coronary heart disease combined. In fact, some 28 million Americans – approximately 13 percent of the population – suffer from migraines. Migraine headaches are characterized by throbbing pain that most commonly originates on one side of the head and may be preceded by fatigue, depression or an aura. Pain may remain localized or spread to both sides of the head. Attacks occur sporadically and can last anywhere from 4 to 72 hours. They may occur only once or twice a year, or as often as daily. Severe pain may be accompanied by a variety of symptoms, including nausea, vomiting, dizziness, fatigue, and extreme sensitivity to light and sound.


Although the least common of the primary headache types, cluster headaches still affect an estimated one million Americans. Some 90 percent of sufferers are male. Cluster headaches start suddenly. The pain usually occurs behind or around one eye and is very severe. Attacks occur in cyclical patterns, or clusters – which gives the condition its name.

Secondary headaches result from other medical conditions, such as meningitis, hemorrhage, and other medical disorders, which can have headache as one of their symptoms. There are over 300 possible secondary causes of headache. The two most common types of secondary headaches are related to head trauma and medication overuse, formerly known as analgesic rebound headache.

Managing Headache

Accurate diagnosis is critical to successful headache management. That being said, both you and your physician need to communicate clearly to effectively diagnose and treat your disorder. Ask your doctor direct and specific questions and make sure you understand the answers. The more clearly and specifically you can communicate your symptoms to your physician, the more likely you are to find relief.

Headaches are diagnosed by matching symptoms to typical headache patterns. Keeping a headache diary can help your doctor identify triggers and isolate precipitating factors that may either contribute to or aggravate your condition. In addition, knowing your family medical history can help your doctor to accurately diagnose a disorder.

Once diagnosed, educating yourself on the type of headache you have and appropriate treatment for it can help you effectively manage it. For many headaches sufferers, some combination of stress management therapy and medication is often an effective way to manage their disorder. Because people react differently to various medications and therapies, you and your physician will need to find the right combination to help you prevent and effectively manage emerging headaches.

The good news is that headache research and treatment are evolving specialties. New and increasingly successful therapies are emerging every day.


  • Alcohol
  • Chocolate
  • Aged cheese
  • Citrus fruits
  • Cured meats
  • MSG
  • Artificial sweeteners
  • Skipped meals
  • Nuts
  • Onions
  • Salty foods
  • Excess caffeine
  • Stress
  • Fatigue
  • Medication
  • Eyestrain/visual triggers
  • Menstruation
  • Weather changes
  • Loud noises
  • Emotions
  • Physical exertion
  • Goals of Treatment

The Quality Standards Subcommittee of the American Academy of Neurology has identified six key goals in the treatment of headache:

  • Reduce attack frequency, severity, and disability
  • Reduce reliance on poorly tolerated, ineffective, or unwanted acute pharmacotherapies
  • Improve quality of life
  • Avoid acute headache medication escalation
  • Educate and enable patients to manage their disease to enhance personal control of their condition
  • Reduce headache-related distress and psychological symptoms