Based on the International Classification of Headache Disorders, there are two main types of headaches: primary and secondary headaches.
Primary headaches are the most common and include the following subtypes:
Tension-type headache: accounting for 69% of primary headaches.
Migraine: representing 16% of primary headaches.
Idiopathic stabbing headache: making up 2% of primary headaches.
Exertional headache: comprising 1% of primary headaches.
Cluster headache: occurring in 0.1% of primary headaches.
Secondary headaches are caused by underlying medical conditions or other factors. The prevalence of various causes is as follows:
Systemic infection: responsible for 63% of secondary headaches.
Head injury: contributing to 4% of secondary headaches.
Vascular disorders: accounting for 1% of secondary headaches.
Subarachnoid hemorrhage: occurring in less than 1% of secondary headaches.
Brain tumor: presenting in 0.1% of secondary headaches.
Specific types of secondary headaches and their characteristics are described below:
Meningitis: Acute and severe headache accompanied by a stiff neck and fever indicates meningitis. Lumbar puncture (LP) is necessary for diagnosis.
Intracranial hemorrhage: An acute and intense headache lasting more than 5 minutes, accompanied by a stiff neck but without fever, suggests subarachnoid hemorrhage. In some cases, a head CT scan may appear normal, requiring LP for definitive diagnosis.
Brain tumor: Approximately 30% of patients with brain tumors report headaches as their primary complaint. The headache is typically dull and intermittent, with moderate intensity. It may worsen with exertion or changes in position and can be accompanied by nausea and vomiting.
Temporal (giant cell) arteritis: This inflammatory disorder primarily affects arteries in the extracranial carotid circulation. The average age of onset is 70 years, and women account for 65% of cases. Symptoms of temporal arteritis include headache, polymyalgia rheumatica, jaw claudication, fever, and weight loss.
Glaucoma: Glaucoma can present with a debilitating headache accompanied by nausea and vomiting. The headache often begins with severe eye pain. Physical examination may reveal a red eye with a fixed, moderately dilated pupil.