Radiation sickness is illness and symptoms resulting from excessive exposure to ionizing radiation.
There are two basic types of radiation: ionizing and nonionizing.
Radiation poisoning; radiation injury
Radiation sickness results when humans (or other animals) are exposed to very large doses of ionizing radiation.
Radiation sickness is generally associated with acute exposure and has a characteristic set of symptoms that appear in an orderly fashion. Chronic exposure is usually associated with delayed medical problems such as cancer and premature aging, which may happen over a long period of time.
The risk of cancer depends on the dose and begins to build up even with very low doses. There is no "minimum threshold."
Exposure from x-rays or gamma rays is measured in units of roentgens. For example:
The severity of symptoms and illness (acute radiation sickness) depends on the type and amount of radiation, how long you were exposed, and which part of the body was exposed. Symptoms of radiation sickness may occur immediately after exposure, or over the next few days, weeks, or months. The bone marrow and gastrointestinal tract are especially sensitive to radiation injury. Children and babies still in the womb are more likely to be severely injured by radiation.
Because it is difficult to determine the amount of radiation exposure from nuclear accidents, the best signs of the severity of the exposure are: the length of time between the exposure and the onset of symptoms, the severity of symptoms, and severity of changes in white blood cells. If a person vomits less than an hour after being exposed, that usually means the radiation dose received is very high and death may be expected.
Children who receive radiation treatments or who are accidentally exposed to radiation will be treated based on their symptoms and their blood cell counts. Frequent blood studies are necessary and require a small puncture through the skin into a vein to obtain blood samples.
The causes include:
Your doctor will advise you how best to treat these symptoms. Medications may be prescribed to help reduce nausea, vomiting, and pain. Blood transfusions may be given for anemia. Antibiotics are used to prevent or fight infections.
If symptoms occur during or after medical radiation treatments:
Feldman R. Radiation injury. In: Schaider JJ, Hayden SR, Wolfe RE, Barkin RM, Rosen P, eds. Rosen and Barkin’s 5-Minute Emergency Medicine Consult. 3rd ed. Philadelphia, Pa: Lippincott Williams & Wilkins; 2007.