Headache is an alarm symptom, whether there is an organic disease (lesional headache) or a perturbation of one of the various functions of the head (functional headache). Lesional headaches follow a sinusitis or an arthrosis, or accompany a "temporal arteritis of Horton". Functional headaches include several varieties. 1. Trigemellar neuralgia. 2. Vascular algia originating from the basal arteries, the large cerebral venous sinuses or the branches of the external carotid. Among these are: a) headaches due to a dilatation of the internal wall, causing "Horton headache", migrain-like psychosomatic migraine and hormonal migraines (premenstrual, menstrual, menopausal or linked to the use of contraceptive pills); b) headaches caused by an angiospasm of the arteriole, which is the case in exposure to the cold, in traumatic headaches (malfunction of temporomandibular articulation, dry alveolitis), in psychosomatic angiospastic algias and in ethmoidal artery algias previously described by the author in 1949 (Godin's disease). 3. Headaches due to psychic hypertension. 4. Postconcussional psychogenic headaches. 5. Neurotic headaches. The author gives a detailed description of the subjective symptoms in each case, including localisation, form, intensity, duration course and associated phenomenons. This facilitates greatly the differential diagnosis and the choice of complementary examinations. Necessary biological investigations should be performed (e.g. hormonal balance). One should however avoid to increase the number of complementary examinations which would only delay treatment and would expose patients to somatisation. Furthermore, in each case drug treatment, periarterial infiltration technics of the temporal, internal frontal, facial, mastoid and occipital arteries are described. The necessity of questioning the patient at length and to listen to him to enable him to verbalise conscious conflicts is emphasized. A serious medicopsychological examination and a relaxation treatment to reduce anxiety and muscular tension are advised in some cases.