Irritable male syndrome (IMS), sometimes called old man syndrome, is defined as a state of hypersensitivity, anxiety, frustration, and anger that occurs in males and is associated with biochemical changes, hormonal fluctuations, stress, and loss of male identity. This term covers symptoms thought to be caused by a drop in testosterone levels in male mammals. It is a striking feature in mammals with seasonal breeding patterns at the end of the mating season.
Irritable male syndrome on Wikipedia.
