It is normal for babies to suddenly always touch their genitals with their hands, probably due to curiosity. However, it may also be caused by too tight underwear or diseases such as eczema. 1. Normal: Since babies are young and curious, they may appear to always touch their genitals with their hands. 2. Too tight underpants: If the baby’s underpants are too tight, it may affect the baby’s movement, thus creating an uncomfortable feeling, which will lead to the baby suddenly always touching the genitals with his/her hands. 3. eczema: the baby suddenly always touch the genitals may also be caused by eczema, eczema is manifested as polymorphic rash, symmetrical distribution, can appear in the genitals and so on, the local itching and other discomforts, which will lead to the baby will be scratched with their hands. The baby suddenly always touch the genitals, there may be other reasons, it is recommended to go to the hospital in time to improve the examination to clarify the cause of the disease, under the guidance of the doctor to give targeted treatment or treatment.