A nervous penis shrinks, then the possible reasons: 1, excessive obesity patients, abdominal wall in front of or before the pubic bone fat pad thicker, the penis hidden in the back of the fat pad, itself appears to be slightly shorter volume, in the nervousness after the sympathetic nerve excitation, the skin and mucous membranes contraction appears to be even more short. In this case, as long as there is no abnormality of urination or erection, weight control is enough, and there is no need for other extra treatments; 2. Hidden penis itself may have a base of fibrosis of the penis fleshy membrane, which makes the size of the penis relatively small, and the excessive contraction of the skin and mucous membranes when emotionally stressed makes the size even more reduced. In this case, it is necessary to go to the hospital for a relevant examination to confirm the existence of cryptogenic penile lesions. If there is such a lesion, then it is necessary to undergo penoplasty to remove the excess fibrosis, in order to restore the normal size of the penis.