Short term

Below 100 rems: No noticable effects

100-200 rems: Nausea approximately three hours after exposure

300 rems: Severe vomiting, loss of hair, hemorrhaging, increased susceptibility to infections due to reduction in white blood cells. Over 50% die within two months.

800 rems: Diarrhea and other problems with digestive organs, dehydration. Over 90% die within two weeks due to failure of the circulatory system.

5000 rems: Severe convulsions and failure of the central nervous system. All cases die within two days.

Long Term (high dosage)

Patients who survive a radiation dose of 600-1000 rads, (a nuclear power plant explosion or a bomb blast, for instance) will experience loss of appetite, nausea, vomiting and bloody diarrhea within four to five hours. These symptoms will persist for several days. Many patients also experience hair and fingernail loss, or fingernails turning black. Blood generating tissues (bone marrow, lymph nodes, thymus gland, and the spleen) will be severely damaged and white blood cell count may decrease from normal levels of around 8000 cells per cubic millimeter to around 50. Consequently, the immune system is seriously compromised. This is known as hematopoietic syndrome from radiation. Many patients who have survived everything else will die at this point from an opportunistic infection, or soon after from failure of the digestive system.

Long Term (low dosage)

People exposed to lower dosages of radiation (less than 600 rem) may have initial sickness and then may develop symptoms up to years later. Long term symptoms of low dosage radiation exposure may include any of the following:

skin disease, anemia, internal disease, arthritis, hearing loss, swelling of the hands and feet, vision loss, weight loss, colitis, nervous disorders, cancer