Transit Disorientation Syndrome
Transit Disorientation Syndrome (TDS, also known as "jump sickness") is a medical condition. While all people suffer from (usually mild) symptoms of dizziness or nausea following a hyperspace jump, TDS describes a stronger reaction to the point of becoming violently ill and/or totally incapacitated.
In February 2108 Raymond Bache became the first human to travel faster than light between Sol's jump points. Some mild concern was expressed when Bache reported experiencing dizziness and nausea immediately following the jump, but continued human testing concluded that such ill effects (symptoms including headaches, mild disorientation, vertigo, nausea and diarrhea) are not possible to mitigate and were deemed acceptable in comparison to the massive benefits of FTL travel. By 3028, a medicine called dralaxine was in common use to mitigate the negative side effects of the K-F jump. 
While this is true for the majority, there is however a number of people, reportedly averaging to between 9 and 15% of the general population, who suffer much more severe reactions to hyperspace jumps which is termed as Transit Disorientation Syndrome. Where normal people recover from a jump within minutes, for TDS sufferers this period may often last for several hours and they will be much more nauseated, irritable and disoriented throughout. Additionally, if a TDS suffer must endure a second jump while still recovering from the first, whether by Command Circuit or aboard a vessel equipped with Lithium-Fusion Battery, the duration of nausea and disorientation can last for days. Cases of heart arrhythmia and psychosis were documented, but are extremely rare.  Studies reportedly show that 83% of all TDS cases with severe symptoms are in fact psychosomatic.
A proactive treatment for TDS involves sedation of such strength that it incapacitates sufferers just as badly. In most cases treatment is reactive, with medical practitioners prescribing rest, hydration and a mild analgesic.
Current medicine offers no reliable method of predicting whether an individual is susceptible to Transit Disorientation Syndrome.  While the condition is tolerated in the ground forces, TDS has ended the career of many a promising spacer or fighter pilot.
- Jihad Conspiracies: Interstellar Players 2, p. 54 "Mysteries of the Void"
- DropShips and JumpShips, p. 10 "To Reach Tau Ceti"
- Warrior: En Garde, p. 238
- The Hunters, p. 143
- A Time of War, p. 127 "Traits - Transit Disorientation Syndrome"
- Explorer Corps, p. 39 "Life in Space - Hyperspace Procedures and Principles - Adverse Health Affects of Hyperspace Jumps"