Headaches can cause general pain occurring throughout the head, or it can be localized to a specific area of the head. There are over 200 types of headaches, and the causes can range from harmless to life-threatening. The causes of headaches can stem from within the cranium itself, or can be referred from the eyes (ophthalmologic), sinuses, or neck or upper back.
It is important to have an in-depth evaluation by a physician to differentiate among the many causes of headaches. Your doctor will need to conduct a thorough history and physical examination, as well as recommend further testing including eye/ear exam, X-rays, CT scans, electroencephalograms (EEG), and MRI imaging to aid in the diagnosis. For these reasons, causes of headaches are grouped into two categories, primary and secondary. Secondary headaches can cause pain due to either benign or malignant causes. Some of these causes will require immediate intervention and may include stroke, intracranial hemorrhage and/or hematoma, infection of the meninges (viral, bacterial, fungal), and malignant hypertension. Benign or malignant tumors may cause pain and headaches become worse as the tumor grows either acutely or gradually. Cataracts and glaucoma can also cause pain and headaches that will require further evaluation by an ophthalmologist. Primary headaches are divided into three basic categories: tension-type headaches, cluster headaches, and migraines.
Tension-type headaches are the most common type of headaches affecting adults. The pain of the headache is a restrictive, band like tension around the head. It can be constant, pressure and squeezing in character occurring on both sides of the head (bilateral). It usually has a slow onset and may last minutes to days. Typical duration is 4-6 hours, but can become chronic.
Cluster headaches are more commonly seen in men, and present as a severe, one-sided (unilateral), pulsating pain around the eye (peri-orbital). Pain can often last 15 min to 3 hours. The pain can also be associated with additional symptoms including drooping eyelid (ptosis), pupil constriction, redness of the conjunctiva, tearing, runny nose, and facial blushing and swelling.
Migraines are headaches that usually occur on one side of the face. The pain is intense, pulsating, and throbbing on one side, but may affect both sides. The pain can be so severe that it becomes debilitating. The pain usually lasts 3 hours to 3 days. Associated symptoms may include nausea, vomiting, light disturbances (photophobia), visual disturbances, smell or taste disturbances. Many precipitating factors can trigger an attack ranging from specific foods, smells, trauma, light, sleep disturbances, emotional distress, and menstrual cycle changes.