Headaches: Cluster - Causes

CAUSES OF SECONDARY HEADACHES

About 90% of people seeking help for headaches have a primary headache. The remainder of cases are secondary headaches, caused by an underlying disorder that produces headache as a symptom. More than 300 conditions can cause headaches. Some of the most common are listed below.

Sinus Headaches. Many primary headaches, including migraines, are misdiagnosed as sinus headaches. Sinus headaches can occur in the front of the face, usually around the eyes, across the cheeks, or over the forehead. They are usually mild in the morning and increase during the day and are usually accompanied by fever, runny nose, congestion, and general debilitation. Sinus headaches spread over a larger area of the head than migraines, but it is often difficult to tell them apart, particularly if headache is the only symptom of sinusitis. Both types of headache even coexist in many cases. Often, the visual changes associated with migraine can rule out sinusitis, but such visual changes do not occur with all migraines. (In rare cases, sinusitis can cause double vision and even vision loss, a sign of very serious infection.)

Headaches that Originate in the Neck. Some headaches may be caused by abnormalities of the neck muscles (called cervicogenic headaches). Nerves in the neck converge in the trigeminal nerve, which is the largest nerve in the skull. It originates in the brain stem and supplies sensation to the face. This nerve can generate pain signals to the facial area that the brain may interpret as headache. Pain is usually on one side. Even if pain affects both sides of the head, it is usually more severe on one side. The quality of the headache may be difficult to distinguish from an aching tension headache or a mild migraine without aura. Cervicogenic headaches can result from prolonged poor posture (such as that caused by sitting in front of a computer keyboard or driving daily for long periods), arthritis, injuries of the upper spine, or abnormalities in the cervical spine (the spinal bones in the neck). Whiplash injuries involve the neck and can cause headaches, which, according to a 2001 British study, resolve within 3 weeks in 85% of patients.

Temporomandibular Joint Disorder (TMJ, also called TMD). Muscle contractions that cause headaches may be a result of temporomandibular joint dysfunction, which is caused by clenching the jaws or grinding the teeth (usually during sleep), or by abnormalities in the jaw joints themselves. The diagnosis is easy if chewing produces pain or if jaw motion is restricted or noisy. TMJ pain can occur in the ear, cheek, temples, neck, or shoulders. This condition often coexists with chronic tension headache.

Glaucoma. Acute glaucoma is caused by increased pressure in the eye and requires immediate medical attention. Throbbing pain may be felt around or behind the eyes or in the forehead. Patients have redness in the eye and may see halos or rings around lights.