Self-detection of breast nodules is mainly done 7-10 days after the end of menstruation through the methods of “seeing, touching, lying down and wringing”. 1. Sight: Look in the mirror and carefully observe the appearance of each breast, its size, skin color or nipple color changes. 2. Touch: you can use the hand coated with soap slippery liquid in the bath or shower to repeatedly carry out the hand checking action, the palm of the hand flat stretching four fingers together, with the index finger, middle finger and ring finger finger finger, in order to make a circle in the way of sliding on the breasts, first from the inside to the outside, and then from the outside to the inside. 3. Lying: Take the lying position, put the right arm under the head, use the left finger to slide to check whether there is a lump on the right side of the breast, touching with a little force. Examine the left breast in the same way. 4. Twist: Gently lift the nipple with the index finger, middle finger and thumb and squeeze it to check carefully for fluid accumulation, then put the four fingers under the armpit to check for lumps. If you find breast nodules in self-check, you should be alert to breast hyperplasia, breast fibroadenoma, plasma cell mastitis, breast cancer and other diseases, and you need to go to the hospital for examination in time, so as to avoid delaying your condition.