There are 2 types of shortenings in penile size which are seen after surgery.First is initial shortening or short term shortening.The initial shortening is thought to occur directly as a result of damage to the nerves traveling around the prostate that are responsible for erections. Damage to these nerves at the time of surgery leads to stimulation and hyperfunctioning of nerves that are part of the sympathetic nervous system. These nerves, responsible for the “fight or flight” response, release adrenaline which leads to contraction of smooth muscle in the body. These sympathetic nerves send impulses to the penis where the smooth muscle of the erectile bodies contract. This contraction of the penis pulls it into the body and makes it appear shorter. Fortunately, this is a short term response which is reversible.Second one is long term shortening ( is irreversible)which can be due to permanent nerve damage experienced during surgery.Moreover ,another cause decreased transport of blood and oxygen through the erectile tissue of the penis: As is widely known, loss of erections is a common side effect of prostatectomy, particularly in the first few months after surgery. Erections lead to the circulation of oxygen-rich blood through the penis which nurtures it and keeps it healthy. If no erections occur for extended periods of time, the lack of circulation of this oxygen-rich blood leads to fibrosis or scarring of the erectile tissue of the penis, also leading it to shrink in terms of length and girth.