Kirk once suffered from a serious bout of Vegan choriomeningitis, a rare disease that can cause death in 24 hours if not treated. Although Kirk survived, his blood continued to carry the disease organisms, which the council of the planet Gideon attempted to use to control the overpopulation on their world ('The Mark of Gideon" [TOS]).
Kirk's relationships with women: James Kirk had several major romances during his life. Ruth (no last name given, seen in "Shore Leave" [TOS]) had apparently been close to Kirk during his days at Starfleet Academy. Endocrinologist Janet Wallace (seen in "The Deadly Years" [TOS]) eventually married Theodore Wallace because both she and Kirk were inflexible in their career choices. Areel Shaw served as Kirk's prosecutor when he was accused of causing Ben Finney's death ("Court Martial" [TOS]). Janice Lester and Kirk evidently shared a year together when Kirk was attending Starfleet Academy ("Turnabout Intruder" [TOS]). Carol Marcus and James Kirk conceived a child, David Marcus, in 2261 (Star Trek II, assumes that David was 24 at the time of the movie, 2285). There has been speculation that Carol Marcus may have been the "blond lab technician" that Kirk nearly married under Gary Mitchell's guidance while they attended Starfleet Academy (circa 2250, "Where No Man Has Gone Before" [TOS]). Of course, this lab technician just as easily could have been Janet Wallace, or some other woman we have not seen. Finally, a woman named Antonia left such a lasting impression that, when in the nexus and given the choice of being with any woman he'd ever known, he chose her. Little else was established about their past relationship, except for the fact that he later regretted not having asked her to marry him.
Kirk once visited the cloud city of Stratos prior to 2269 ("The Cloud Minders" TOS]), but noted it was only a brief visit and he didn't have time to look around.
Kirk's retirement: Star Trek Generations establishes that Kirk retired from Starfleet sometime before 2282. We conjecture that he retired in 2281. We don't know much about this time, except that he met Antonia at his uncle's farm in 2282, and was living with her in his mountain cabin at the time he decided to return to Starfleet in 2284, nine years before the launch of the Enterprise B. (Kirk apparently met Antonia during this time.) Kirk's second retirement was in 2293, just after Star Trek VI.
Kirk was believed killed shortly after the launch of the Enterprise B in 2293 (Star Trek Generations), but it was later learned that he was alive in the nexus, where he remained until 2371. Kirk was killed shortly after emerging from the nexus, and he was buried on a mountaintop on planet Veridian III. Key data points from Kirk's life include: 2233: Born in Iowa on Earth (conjecture).
2250: Admitted to Starfleet Academy, serves aboard U.S.S. Republic (conjecture, "Court Martial" [TOS]).
2254: Graduated from Starfleet Academy, begins serving aboard U.S.S. Farragut (conjecture, "Obsession" [TOS]).
2261: Had son, David, with Carol Marcus (Star Trek II: The Wrath of Khan).
2263: Assumes command of Enterprise (conjecture).
2269: Returns from five-year mission, promoted to Admiral (Star Trek: The Motion Picture).
2271: Reassigned as Enterprise captain (Star Trek: The Motion Picture).
2281: Retires from Startleet (Star Trek Generations).
2284: Returns to Starfleet, leaving Antonia (Star Trek Generations).
2286: Convicted of violating Starfleet orders (Star Trek IV The Voyage Home).
2286: Assigned to command Enterprise A (Star Trek IV The Voyage Home).
2293: Retires again, believed killed at launch of Enterprise B (Star Trek Generations).
2371: Emerges from nexus, killed at Veridian III (Star Trek Generations).