Around the age of 66 Cajal consulted neurologist Nicolas Achúcarro complaining of “unbearable cephalalgias”. He had not ever suffered from headaches. The diagnosis of early arteriosclerosis that was considered at the time a physiological, irreversible ailment of ageing had a strong emotional impact on Cajal. Comorbid depression, insomnia and self-treatment with escalating doses of Veronal^® (barbital), a short-acting barbiturate, presumably aggravated the situation. Exposure to warm environments and being involved in tense discussions were identified as triggering factors of the headaches. Achúcarro and Cajal were probably assuming scientific concepts at the time, such as cerebral congestion, increased temperature at the cerebral cortex during mental activity and vasoconstriction and vasodilatation phenomena. Up to his death aged 82, no evidence was discovered of any organic nervous system disorder. Cajal remained anxious up to the end of his life fearing an impending cerebral haemorrhage. The diagnosis was followed by profound lifestyle changes such as social isolation, which forced him to leave his laboratory. Cajal's cephalalgias marked in some way the end of the Spanish school of neurohistology.