Anejaculation is the pathological inability to ejaculate in males, with (orgasmic) or without (anorgasmic) orgasm. It can depend on one or more of several causes, including (ordered by frequency)':
Anejaculation, especially the orgasmic variant, is usually indistinguishable from retrograde ejaculation. However, a negative urinalysis measuring no abnormal presence of spermatozoa in the urine will eliminate a retrograde ejaculation diagnosis. Thus, if the affected man has the sensations and involuntary muscle-contractions of an orgasm but no or very low-volume semen, ejaculatory duct obstruction is another possible underlying pathology of anejaculation.