Physiology is the branch of biology that deals with the functions of living organisms and the parts of which they are made. This scientific discipline covers a wide variety of functions, ranging from the cellular and below to the interaction of organ systems that keep the most complex biological machines running.
PTSD redirects here. For the album by Pharoahe Monch, see PTSD (album). Posttraumatic stress disorder (PTSD) is a mental disorder that can develop after a person is exposed to a traumatic event, such as sexual assault, warfare, traffic collisions, or other threats on a person's life.
PTSD was once considered a psychological condition of combat veterans who were âshockedâ by and unable to face their experiences on the battlefield. Much of the general public and many mental health professionals doubted whether PTSD was a true disorder.