The causes of short penis in newborns include physiological and pathological ones, and the pathological causes include prepuce, short penis syndrome, etc. The treatments include medication such as hormonal drugs, surgery, and so on. 1. Physiological factors: the newborn’s body development is still immature, the sex organs are not yet fully developed and the penis is stretchy, so it can be manifested as a short penis. In addition, newborns are fat, body fat will appear short penis, with the growth of age and physical development, can gradually return to normal. 2. Pathological factors: the symptoms of penile shortness, erection pain and so on. Treatment includes medication such as mometasone ointment, boric acid water solution, etc. Surgical treatment such as circumcision can also be performed. Symptoms of short penis syndrome are penis smaller than normal length. Medication includes chorionic gonadotropin, testosterone, etc. In severe cases, the condition can be treated by surgery, and the choice of medication needs to be made under the guidance of a doctor. When the child becomes unwell, he should go to the hospital immediately. The above medications should be applied under the guidance of a doctor.