not noramlly for any plain plate X-ray tests, eg. chest/abdominal x-ray; but certain people do experience nausea and vomiting when contrast is used for the procedure. The adverse effects usually does not last long and subside within hours.
is somewhat weak and unhealthy, then he/she may feel uncomfortable ---- Not necessarily due to X-ray per se, maybe due to something else (e.g., noise, even just mental stress: 太紧张)