radiation sickness, an abnormal condition resulting from exposure to ionizing radiation. The severity of the condition is determined by the intensity of radiation, the length of time of exposure, and the area of the body affected. Moderate exposure may cause headache, nausea, vomiting, anorexia, and diarrhea; long-term exposure may result in sterility, leukemia or other forms of cancer, alopecia, and cataracts.
