Over a lifetime, a person typically receives 7 to 14 rems from natural sources of radiation, such as cosmic rays. A single exposure of 5 to 75 rems produces few observable symptoms. Vomiting, fatigue, and loss of appetite accompany exposures of 75 to 200 rems, and recovery takes a few weeks. Severe changes in blood cells and hemorrhage occur with exposures of more than 300 rems. Above 600 rems, additional symptoms include loss of hair and loss of the body's ability to fight infection, usually resulting in death.
Doctors can treat only the symptoms of radiation sickness.
Blood transfusions and the use of antibiotics to fight infection are common treatments. W. Emmett Bolch, Ph.D., Professor of Environmental Engineering, Univ. of Florida. How to cite this article.