The Full Enchilada

Radiation first affects the intestinal system causing nausea, vomiting, diarrhea, weakness, and even death. The thyroid is also affected soon after and is the reason people are given iodine tablets, so as to lessen the impact and provide the thyroid clean iodine to absorb versus the radiation laden iodine from the nuclear fallout. (Wine supposedly helps somewhat also due to the tannins, but then any strong anti-oxidants should help.)

Other symptoms include loss of appetite, red itchy skin, sore mouth and throat, anemia, hair loss, bleeding, recurrent infections, and of course all kinds of cancers if not exposed to high enough levels to cause death in days or weeks.