Inability to ejaculate (anejaculation) is usually caused by inability to reach orgasm (anorgasmia). It usually occurs as part of erectile dysfunction. (See also Overview of Sexual Dysfunction in Men.)
The cause is usually prostate surgery because
The nerves between the spinal cord and the penis may be damaged during pelvic surgery.
Removal of the prostate and seminal vesicles during surgery for prostate cancer eliminates the ability to produce semen (these glands are involved in semen production).
Other conditions that damage the nerves of the penis, as well as some mental disorders and some drugs that are used to treat mental disorders, may also affect the ability to ejaculate.
Retrograde ejaculation can sometimes result in absence of visible semen.
Depending on the cause, anejaculation may occur with or without orgasm. A doctor bases the diagnosis of anejaculation on the man's symptoms, results of an examination, and, if orgasm is possible, a urine test. Absence of sperm in a urine sample obtained after an orgasm indicates anejaculation, whereas presence of many sperm indicates retrograde ejaculation.
