Headache is generally regarded as a symptom of high blood pressure in spite of conflicting opinions on the association of headache and arterial hypertension. Most studies have shown that mild chronic hypertension and headache are not associated and this demonstration needs to be implemented in clinical practice. Whether moderate hypertension predisposes to headache remains controversial, but there is little evidence that it does. Headaches caused by significant disturbances in arterial pressure are included in the section "Headache attributed to a disorders of homeostasis" (code 10.3) of the 2nd edition of the International Classification of Headache disorders.