Acute Radiation Syndrome (ARS): A Fact Sheet for the Public
Acute Radiation Syndrome (ARS), or radiation sickness, is a serious illness that can happen when a person is exposed to very high levels of radiation, usually over a short period of time. The amount of radiation that a person’s body absorbs is called the radiation dose.
People exposed to radiation will get ARS only if:
- The radiation dose was high
- The radiation was able to reach internal organs (penetrating)
- The person's entire body, or most of it, received the dose
- The radiation was received in a short time, usually within minutes.
Symptoms of ARS
- Symptoms of ARS may include nausea, vomiting, headache, and diarrhea.
- These symptoms start within minutes to days after the exposure, canlast for minutes up to several days, and may come and go.
- If you have these symptoms after a radiation emergency, seek medical attention as soon as emergency officials determine it is safe to do so.
- After the initial symptoms, a person usually looks and feels healthy for a period of time, after which he or she will become sick again with variable symptoms and severity that vary depending on the radiation dose that he or she received.
- These symptoms include loss of appetite, fatigue, fever, nausea, vomiting, diarrhea, and possibly even seizures and coma.
- This seriously ill stage may last from a few hours up to several months.
- People who receive a high radiation dose also can have skin damage. This damage can start to show within a few hours after exposure or it may be delayed for several days. It can include swelling, itching, and redness of the skin (like a bad sunburn) or may be more severe and include blisters or ulcers.
- The skin may heal for a short time, followed by the return of swelling, itching, and redness days or weeks later.
- Complete healing of the skin may take from several weeks up to a few years.
- The time for skin to heal depends on the radiation dose the person’s skin received.
- People who receive a high radiation dose to all or part of the body also may experience temporary hair loss. It may take several weeks for the hair to grow back.
Treatment of ARS
- Treatment of ARS focuses on reducing and treating infections, maintaining hydration, and treating injuries and burns. Some patients may benefit from treatments that help the bone marrow recover its function.
- The lower the radiation dose, the more likely it is that the person will recover from ARS.
- The cause of death in most cases is the destruction of the person's bone marrow, which results in infections and internal bleeding.
- For survivors of ARS, the recovery process may last from several weeks up to 2 years.
- Cutaneous Radiation Injury (CRI) happens when exposure to a large dose of radiation causes injury to the skin. A doctor will suspect the presence of a CRI when a skin burn develops in a person who was not exposed to a source of heat, electrical current, or chemicals.
People with ARS typically also have some skin damage. This damage can start to show within a few hours after exposure and can include swelling, itching, and redness of the skin (like a bad sunburn).
There also can be hair loss. As with the other symptoms, the skin may heal for a short time, followed by the return of swelling, itching, and redness days or weeks later. Complete healing of the skin may take from several weeks up to a few years depending on the radiation dose the person's skin received.
- Page last updated August 22, 2013
- Page last reviewed August 22, 2013
- Content source: Radiation Studies Branch (RSB), Division of Environmental Hazards and Health Effects (EHHE), National Center for Environmental Health (NCEH), Coordinating Center for Environmental Health and Injury Prevention (CCEHIP)
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