Headaches can range from the annoying to the dangerous, and anywhere in between. Frequent, severe headaches can disrupt daily life and can lead individuals to seek relief from doctors or the emergency department.

Headaches are often divided into two categories. Those unrelated to a medical condition are called primary headaches, while headaches stemming from medical conditions are called secondary headaches.

While more than 200 types of headaches have been identified by the International Headache Society, the vast majority of headaches are tension headaches, a type of primary headache.

Women are generally more likely than men to have headaches, but some types occur more frequently in men. Children can also be affected by headaches.

Article continues below

How a Headache Develops

Headaches are not caused by pain within the brain due to the fact that there are no nerve receptors that perceive pain within the brain tissue. Instead, pain starts in sensitized nerves, muscles, and blood vessels near the brain and in the scalp, neck, and face.

Swelling or muscle tightness in this area can cause nerves to send pain signals to the brain, resulting in a headache. The action setting a headache in motion is often not clear, but may include:

  • Drinking alcohol
  • Eating a certain food
  • Having an illness or medical condition
  • Getting insufficient sleep
  • Having a nutritional deficiency
  • Working long hours, especially at a computer
  • Skipping meals
  • Clenching the jaw
  • Experiencing stress

Headaches can develop suddenly or gradually and last from hours to days, depending on the type of headache.

When Headaches Are an Emergency

In some instances, a headache can be a sign of a serious problem. If a headache is unusually painful, occurs suddenly, and feels like the most intense headache of your life, a trip to the emergency room or calling 911 is advised.

Immediate medical attention is also needed if a headache includes:

  • Convulsions
  • Slurred speech, sudden numbness or inability to move around normally
  • A stiff neck, confusion, or fever
  • A recent impact to the head
  • Ear or eye pain
  • Fainting or a loss of consciousness
  • Vomiting or queasiness for no apparent reason
  • Persistent vision loss
  • Shortness of breath

Such symptoms may point to a stroke, spinal meningitis, or an aneurism—all major medical issues.

Children with recurring headaches and people with medical conditions who develop a headache should also see a doctor.