The absence of nipple holes may be related to inverted nipple, congenital underdevelopment and acquired factors. 1. Nipple inversion: If the patient’s nipple inversion is more serious, it will cause the whole nipple to fall into the areola, and the nipple will not be exposed, so naturally, you can’t see whether there is any hole on the nipple. 2. Insufficient congenital development: in the process of embryo formation and development, if the mother uses some drugs or comes into contact with a lot of radiation, it may make the embryonic tissues underdeveloped, resulting in the formation of nipples with no holes, and other deformities and other phenomena. 3. Caused by acquired factors: after excluding the congenital factors, we need to consider that it is caused by some accidental factors during the puberty development stage. For example, wearing too tight underwear, nipple trauma, mastitis and so on. As the nipple without holes will affect normal breastfeeding, it is best for women to consult a doctor in a timely manner, do a systematic examination, and actively cooperate with the doctor’s treatment.