Space sickness
From Memory Alpha, the free Star Trek reference.
Space sickness is a psychological condition caused by being off of a planet's surface. Its symptoms include nausea and disorientation. Space sickness is stronger when there is turbulence on a ship. In many ways, space sickness is the deep space equivalent to sea sickness. Just as an experienced sailor is said to have "sea legs", experienced space travelers are said to have "space legs".
In 2267, Chekov joked to Sulu that frequent course changes between Vulcan and Altair VI were making him space sick. (TOS: "Amok Time")
Ezri Dax suffered from this condition after being joined to her symbiont. (DS9: "Shadows and Symbols")
In 2375, a number of USS Voyager crew members reported symptoms of space sickness, which were found to be the result of temporal distortions produced by a temporal disruptor. (VOY: "Relativity")
