The follicular phase is the period of preparation for ovulation, which begins on the day of menstrual cessation and ends on the day the ovaries ovulate, usually lasting about 10-14 days, with some variation depending on the individual’s body type, but usually not too much. The normal menstrual cycle includes the menstrual phase, follicular phase, ovulation phase and luteal phase. During the follicular phase, some primordial follicles begin to grow and develop, but eventually only 1 follicle will mature and ovulation will occur, while the others will gradually shrink and eventually form an atretic follicle. Normally, the size of follicles in the follicular phase is between 2-9mm and the number is less than 10. If the number is more than 10, it is important to consider the presence of ovarian polycystic-like changes. It is recommended that women should cultivate the habit of regular work and rest in daily life, avoid staying up late, pay attention to keeping warm, try to avoid frequent consumption of cold, spicy and stimulating foods, and also exercise regularly to improve the immunity of the body.