What is a headache? Definition

Headache, also referred to as cephalgia in medicine, is a continuous ache or pain in the region of the head or upper neck. It can last from a few hours to a few days depending on the cause and the type of headache.

It is probably the most common symptom of man and almost all of us have experienced it and will experience it throughout life.

The type of headache pain varies. It may be severe or mild, acute or chronic. It may affect one part of the head or the whole head.

The pain may be constant and dull, or it may be sudden or sharp or throbbing and pounding. At times, it may be accompanied by other symptoms such as nausea or vomiting.

Headache is a symptom of an underlying cause and all these variations depend on the type and cause of this pain. Most of its causes are not dangerous but some can be life-threatening, and they are rare.

There are probably more causes for headaches than for any other symptom in the body and they run across almost all systems of the body.

The pathophysiology of a headache is still being propounded and not fully understood and confirmed. Whatever is known is mentioned below.

The brain has no pain receptors and therefore, the head pain does not originate from brain tissue.

The pain receptors are situated in the blood vessels, nerves, muscles, membranes, and other related structures in the skull and neck.

It is the dysfunction or hyperactivity in these tissues, which gives rise to the pain of a headache.

Types of headaches

In 2007, the International Headache Society updated the classification system of headaches in order to facilitate a better diagnosis of the cause and better treatment.

Here, we discuss different types of headaches, which will also help you understand the type you are suffering from. 

Headache is of two types and is classified according to its causes:

  1. Primary headaches are tension headaches, migraines, and cluster headaches. They are all due to benign causes.
  2. Secondary headaches are due to some underlying pathology anywhere in the body.

1. Primary headaches

A primary headache is the most common type. There are various causes of primary headaches and all are benign without a life-threatening cause. Primary headaches are not due to any underlying pathological cause. They are due to disturbances in the pain-sensitive areas in the head and neck.

Some people get headaches due to a genetic cause as they carry genes, which make them more prone to getting them. Primary headaches are again sub-classified into three types.

  • Tension headache. Tension headache is the most common type of primary headache usually seen in women above the age of 20 years.  As many as 90% of adults suffer from tension headaches. They are more common among women than men. This type of headache typically feels like a tight band around the scalp on both sides of the head and is due to the tightening of the muscles of the scalp and neck. It may last for a very short time or may extend for days. This headache is a result of mental stress and/or bad posture affecting the head and neck and is aggravated by noise and a hot climate. It often develops during midday and has no other accompanying symptoms like vomiting and nausea, which you typically see in migraine.
  • Migraine headaches. Migraine headaches are intense and of throbbing nature and often felt on one side of the head. They can last from a few hours to three days. Before puberty, the incidence of migraine is equal among children of both sexes but after puberty, it is seen more in women. About 5% of school-going kids and 10% of teenagers suffer from migraine. A migraine sufferer usually has recurrences, which can range from several times a month to about once a year. The frequency of migraine attacks reduces with advancing age. In the US, about 28 million people suffer from migraine attacks every year. Migraine is precipitated and aggravated by certain trigger factors such as exposure to the hot sun or seeing a movie or missing a meal, certain medications, and other aggravating factors.
    • Migraine with aura is a type of migraine headache, which is often preceded by symptoms such as nausea, vomiting, dizziness, sensitivity to light, etc. A migraine without aura does not have any preceding symptoms before the headache sets in.
  • Cluster headaches. Cluster headaches are rare and affect about one in a thousand people. Men, women, and children can all be affected but it is seen more commonly in men who are in their late twenties. They occur periodically, with remissions interrupting active cluster periods. The pain of cluster headaches is of severe intensity and more than the other types of headaches described above. It is usually felt in the area around the eye and the temple region.

2. Secondary headaches

Secondary headaches are due to pathology in the head and/or neck. They require medical intervention to correct the cause. The severity of secondary headache pain varies depending on the cause.

Some of the causes of secondary headaches are harmless like pain due to inflammation of neck muscles or due to side effects of a medication or a hangover from drinking alcohol.

But some causes can be dangerous like stroke (blockage of an artery or bleeding in the brain), meningitis, encephalitis, or a brain tumor.

You should consult a doctor if you have a headache of long-standing duration accompanied by certain out-of-the-way symptoms and causing disability.

How do you get a headache?

Contrary to popular belief among the general population, headache pain is not felt by brain tissue because brain tissue does not have pain receptors.

It is felt due to certain dysfunction or hyperactivity in areas around the brain, which are pain-sensitive. These areas around the brain are the

  • muscles,
  • arteries,
  • veins,
  • nerves,
  • eyes,
  • ears,
  • sinuses,
  • mucous membranes and
  • the periosteum of the bony skull (connective tissue membrane, which lines the outer surface of the skull).

Headache due to vascular causes is the most common. This headache occurs due to dilation of the arteries in and around the brain caused by hunger, hangover, deprivation of caffeine, certain medications, etc.

Due to its prevalence, headache is a concealed epidemic and yet is not considered a serious medical problem.

Statistics and Facts

  • 70% of people experience headaches at least once throughout the year.
  • Approximately, 45 million Americans suffer from this chronic condition.
  • Depression is three times more common in people with chronic headaches than in healthy individuals.
  • Women are three times more prone to a headache than men.
  • It is seen most commonly between the ages of 30 to 39 years.
  • About 12 billion dollars are lost in productivity due to headaches by way of direct and indirect costs.
  • Over $2 billion is spent in the United States on over-the-counter medicines for this condition.
  • Over the period of two decades from 1972 to 1991, the prevalence of pediatric headaches increased from 14% to 50%.
  • It can be caused by benign factors or serious life-threatening ones.