Introduction Because some secondary hypertension would be cured by surgery or other special methods, it's important to diagnosis correctly aetiology of hypertension.

Methods Retrospective study was performed based on aetiology of in-patients with hypertension in department of hypertension of Xinjiang from September 1997 to December 2005. 2436 male and 2206 female, with average age was 53.57±13.14 were analysed.

Results (1) Of 4642 in-patients with hypertension, there were 85.24% of essential hypertension and 14.76 % of secondary hypertension (SH). Higher prevalence rate of secondary hypertension were sleep apnoea syndrome (42.92%) and anxiety (15.04%). Highest prevalence rate of endocrine hypertension was primary aldosteronism (12.12%). (2) The male with hypertension was more than the female, the prevalence of essential hypertension (EH), sleep apnoea syndrome (SAS), primary aldosteronism (PA) in male were higher than those of female; the prevalence of anxiety, pheochromocytoma, renovascular hypertension in female were higher than those of male. (3) There was 21.9% of SH in youth and 9.85% of SH in older.

Conclusion For the youth, SH should be excluded, especially SAS and anxiety. The highest prevalence rate of endocrine hypertension was primary aldosteromsm in youthful and middle aged male. The prevalence rate of pheochromocytoma in female was higher than those of male.