Acute Radiation Syndrome (ARS)

a serious illness caused by receiving a dose greater than 75 rads of penetrating radiation to the body in a short time (usually minutes). The earliest symptoms are nausea, fatigue, vomiting, and diarrhea. Hair loss, bleeding, swelling of the mouth and throat, and general loss of energy may follow. If the exposure has been approximately 1,000 rads or more, death may occur within 2 – 4 weeks. For more information, see CDC’s fact sheet “Acute Radiation Syndrome” at emergency.cdc.gov/radiation/ars.asp.