Micropenis, or microphallus, is a condition where a stretched penis measures less than 2.5 standard deviations below the average penis size per age.

Commonly male adolescents consult a urologist impelled by concerns about the size of their penis.

In most cases these boys have a normal penis.

On many occasions, the cause may be co-existing obesity, as it gives a false impression of a small penis which is hidden inside the surrounding fat.


Micropenis may not be associated with distinct causes (idiopathic) or may be due to hormonal disorders, the main ones being:

  • Hypogonadotropic Hypogonadism: due to pathology of the hypothalamus
  • Hypergonadotropic Hypogonadism: due to testicular damage resulting in reduced production of testosterone


Requires appropriate measuring of the penis and ruling out of any congenital anomalies affecting its size.

The following must be assessed:

  • Size, position and composition of the testicles
  • Blood tests are necessary to evaluate hormonal disorders


  • Children with hormonal disorders must be referred to a pediatric endocrinologist
  • Hormonal therapy may be administered to increase penile length
  • Should hormonal therapy fail, surgical penile enlargement techniques are available