Today we will look at the pathogenesis of headaches. Headache occurs primarily from excessive firing of nerve fibers in pain-sensitive tissues of the head, or from normal firing of these structures but abnormal psychological responses. Because the head and face are richer in nociceptive receptors than other parts of the body, more headaches are complained of than various other pains throughout the body. 1. The cranial structures that are more sensitive to pain are: (1) scalp, subcutaneous tissues, muscles, arteries, skull periosteum, orbital contents, external and middle ears, nasal cavity and sinuses, etc.; (2) intracranial venous sinuses and their branches, meningeal arteries, basilar artery ring and its main branches, part of the dura mater at the base of the brain, the 5th, 7th, 9th and 10th cerebral nerves and the 1st, 2nd and 3rd cervical nerves. The brain parenchyma, soft meninges, arachnoid and most of the dura mater, ventricular canal, choroid plexus and the skull itself are not sensitive to pain. 2. The mechanisms of headache include: (1) vascular factors: contraction and dilation of intracranial and extracranial blood vessels caused by various reasons and traction or stretching of blood vessels (traction and extrusion of blood vessels by intracranial occupying lesions); (2) stimulation or pulling of meninges; (3) stimulation, extrusion or pulling of brain nerves with pain sensation (trigeminal nerve, facial nerve, glossopharyngeal nerve, vagus nerve) and the 1st, 2nd and 3rd cervical nerves; (4) stimulation, extrusion or pulling of head and cervical muscles; (5) stimulation, extrusion and pulling of head and cervical nerves. ) contraction of the head and neck muscles; (5) lesions of the five senses and cervical spine; (6) biochemical factors and endocrine disorders; (7) neurological disorders.