Ulcer - a break in skin or mucous membrane. Stomach ulcers have long been associated with stress or anxiety, however, anxiety alone is not the cause of stomach ulcers. See helicobacter pylori.
Unconscious - any thought or mental process that we are unaware of. Contrast with conscience and conscious.
Unipolar - a form of manic depression that only involves the depressed emotional state.
Uterus - a female reproductive organ. The uterus (womb) produces chemical messengers related to anxiety disorders. The womb's relation to anxiety disorders may become pronounced during menstruation or pregnancy, or via it's absence after a hysterectomy.