Precautions for female cancer screening are as follows: First, breast screening should be performed after menstruation, not before menstruation. Because the progesterone level is higher before menstruation, physiological breast enlargement is likely to occur, so the examination is prone to problems. After menstruation, all hormone levels of the patient are at a low level, which has a small effect on the breast, and the results of the examination are more realistic. Secondly, if screening of the cervix is performed, it is important to choose a time when the patient is not bleeding vaginally for the test. If the patient has vaginal bleeding, the cells at the squamous-columnar junction of the patient’s cervix will be washed out during the test, so the test results will be inaccurate. It is recommended that the best time to perform the test is after ovulation. The cells shed at the cervix will be more abundant, so there is usually no insufficient sampling when taking the material, and the test results are relatively accurate.