Hematologic | Dose: Approximately 1–10 Gy (100–1,000 rad) |
| Clinical symptoms: General injury of blood-forming cells in bone marrow, which increases with increasing dose, leading to pancytopenia. This results in bleeding, anemia, hemorrhage, malaise, and severe, often fatal, infection. |
| Treatment: |
| 0–1 Gy (0–100 rad)—Reassurance |
| 1–2 Gy (100–200 rad)—Reassurance and hematologic surveillance |
| 2–6 Gy (200–600 rad)—Blood transfusion and antibiotics |
| 6–10 Gy (600–1,000 rad)—Consider bone marrow transplant |
| Without treatment, no one has survived a single abrupt dose of 5 Gy (500 rad) or higher. It is possible to survive the hematologic syndrome with a bone marrow transplant, but at higher doses all subjects will die from the gastrointestinal syndrome. |
Gastrointestinal | Dose: Approximately 2–50 Gy (200–5,000 rad) |
| Clinical symptoms: Nausea, vomiting, and diarrhea; prolonged diarrhea; dehydration; electrolyte imbalance; lethargy; anorexia; death above 10 Gy (1,000 rad) with no treatment. |
| Treatment: |
| 2–6 Gy (200–600 rad)—Blood transfusion and antibiotics |
| 6–10 Gy (600–1,000 rad)—Consider bone marrow transplant |
| 10–50 Gy (1,000–5,000 rad)—Maintenance of electrolyte balance |
| At about 2 Gy (200 rad), classic radiation sickness (nausea, vomiting, and diarrhea) may begin because of radiation injury to the gastric and intestinal mucosa. |
Central nervous system | Dose: >50 Gy (>5,000 rad) |
| Clinical symptoms: Ataxia, convulsions, lethargy, coma, death |
| Treatment: Sedatives |