The best time for endocrine examination, i.e. sex hormone examination, is recommended on the 3rd day of menstruation for women, and can be performed at any time for men. For women, endocrine examination mainly refers to the sex hormone six, which can reflect the regular changes of hormones in women’s menstrual cycle, including follicular phase, pre-ovulatory phase, ovulatory and luteal phases, and menopause. The endocrine test has its normal reference range at any stage. However, although usually, women ovulate around the 14th day of menstruation, therefore, it is recommended that women check their endocrine hormones preferably on the 3rd day of menstruation, which can reflect the most basic hormone levels. Some women do not have menstruation for a long time, and due to the endocrine hormone disorder there is no way to restore normal menstruation, so there is no time limit at this time, and blood tests can be performed without menstruation. For men, endocrine tests can be performed at any time, and fasting is sufficient before the test. When endocrine disorders occur, it is important to visit the endocrinology department of the hospital in time for relevant examinations to avoid infertility, amenorrhea and infertility.