This page contains information regarding Star Trek: Discovery, and thus may contain spoilers.
Space sickness was often brought on by turbulence on a ship, or inertial dampeners being out of alignment, and was especially strong if a ship lacked artificial gravity. In many ways, space sickness was the deep space equivalent to sea sickness. Just as an experienced sailor was said to have "sea legs", experienced space travelers were said to have "space legs". (ENT: "Sleeping Dogs", "The Xindi", TOS: "The Lights of Zetar") Nonetheless, most space travelers experienced space sickness from time to time. Space sickness could be treated by inaprovaline. (VOY: "Relativity")
In the 23rd century, in the medical history section of Christopher Pike's personnel file, space sickness was listed with other ailments he had suffered during his lifetime prior to 2257. (DIS: "Brother")
In 2374, B'Elanna Torres, while floating in space with Tom Paris, told him that the experience of being in space with EV suits was nothing like the simulations at Starfleet Academy and it made her feel a little sick to her stomach. (VOY: "Day of Honor")
Doctor Julian Bashir handed Ezri Dax twenty milligrams of a medicine in a hypospray when she boarded the runabout to Sappora VII and told her it should help her with her space sickness. (DS9: "Prodigal Daughter")