Clinical syndrome seen at doses >100-200 rad (1-2 Gy)
Smaller doses cause clinically insignificant pancytopenia
Lymphocytes depleted first, then granulocytes, platelets, and RBCs
Lymphocyte depletion is predictable based on dose
Death usually secondary to infection or hemorrhage and poor healing
Doses >350 rad fatal within several months if untreated
Smaller doses cause clinically insignificant pancytopenia
Lymphocyte depletion is predictable based on dose
Doses >350 rad fatal within several months if untreated
Syndrome occurs at 600-1000 rad (6-10 Gy)
Abdominal pain, nausea/vomiting, diarrhea, ileus
Death occurs within weeks secondary to multiorgan failure and sepsis if untreated
Syndrome occurs at >1000-2000 rad (10-20 Gy)
At this dose, vomiting is suppressed
Dizziness, LOC, papilledema, ↓ DTRs, ataxia, coma
Doses >3500 rad (35 Gy) damage large blood vessels → cardiovascular failure, cerebral edema
Doses >5000 rad (50 Gy) cause death within 48 hours
At this dose, vomiting is suppressed
Dizziness, LOC, papilledema, ↓ DTRs, ataxia, coma
Each<unk>  syndrome typically progresses through 4 stages of disease
Characterized by nausea and vomiting
Other symptoms include: malaise, fever, conjunctivitis
Doses over 1000 rad (10 Gy), vomiting is not seen in early symptoms
Occurs within 48h-6d of exposure (at higher doses, can begin within minutes)
Lasts up to 2 days
Other symptoms include: malaise, fever, conjunctivitis
Doses over 1000 rad (10 Gy), vomiting is not seen in early symptoms
Short period of symptom improvement
Lasts several days to 1 month
Manifestation of symptoms of clinical syndromes
Severity based on, among other things:
Overall dose
Irradiated body volume
Comorbidities and overall health status
Age
Characterized by significant immunosuppression
Lasts for days to months
Overall dose
Irradiated body volume
Comorbidities and overall health status
Age
If patient survives manifest illness stage, recovery is slow (weeks to years)
If lethal dose received, death can occur within days (very high, rapid doses) or may be delayed up to several months
Doses over 1000 rad (10 Gy) are uniformly fatal
Acute radiation syndrome
Radiation exposure 
Epidural compression syndromes
Dirty bomb
Acute mountain sickness
Bioterrorism
Decompression sickness
Chemical weapons