A number of symptoms that appear to be associated with high blood pressure (headache, dizziness, epistaxis, tinnitus, weakness, drowsiness), and are usually regarded as secondary to hypertension or to antihypertensive drug therapy, were studied in 3858 elderly patients, 67.8% of whom were hypertensive. Of the hypertensive patients, 71.2% were under treatment. Headaches and dizziness were significantly more prevalent in the hypertensive than in the normotensive subjects (32.5 versus 27.4% and 41.5 versus 35.3%, respectively; P less than 0.05) and in treated compared with untreated hypertensives (33.3 versus 29.4% and 43.3 versus 37.1%; P less than 0.05). These differences disappeared after statistical correction for 'awareness of hypertension'. In multiple logistic analysis, female sex, age and awareness of hypertension were significantly associated with a higher prevalence of symptoms, whereas hypertension and antihypertensive treatment were not. We conclude that the presence of these symptoms does not constitute a reliable criterion for starting antihypertensive treatment or judging its efficacy.