What Causes Headaches?

Headache pain results from signals interacting among the brain, blood vessels and surrounding nerves. During a headache, specific nerves of the blood vessels and head muscles are activated and send pain signals to the brain. It’s not clear, however, why these signals are activated in the first place.

There is a migraine "pain center" or generator in the mid-brain area. A migraine begins when hyperactive nerve cells send out impulses to the blood vessels, causing constriction, followed by the dilation of these vessels and the release of prostaglandins, serotonin and other inflammatory substances that cause the pulsation to be painful. Serotonin is a naturally occurring chemical essential for certain body processes.

Headache Onset

Headaches that occur suddenly (acute onset) are usually caused by an illness, infection, cold or fever. Other conditions that can cause an acute headache include sinusitis (inflammation of the sinuses), pharyngitis (inflammation or infection of the throat) or otitis (ear infection or inflammation).

In some cases, the headaches may be the result of a blow to the head (trauma) or, rarely, a sign of a more serious medical condition.

Causes and Symptoms

Common causes of tension headaches or chronic nonprogressive headaches include emotional stress related to family and friends, work or school, alcohol use, skipping meals, changes in sleep patterns, excessive medication use tension and depression. Other causes of tension headaches include eye strain and neck or back strain caused by poor posture.

When chronic headaches become progressive and occur along with other neurological symptoms, they can be the sign of a disease process in the brain (organic cause), such as:

• Abscess
• Blood clots
• Encephalitis (inflammation of the brain)
• Head trauma
• Hemorrhage (bleeding within the brain)
• Hydrocephalus (abnormal buildup of fluid in the brain)
• Infection of the brain
• Meningitis (an infection or inflammation of the membrane that covers the brain and spinal cord)
• Toxins (overexposure to chemicals from certain medications, such as selective serotonin-reuptake inhibitors Prozac or Zoloft)
• Tumor