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Time Phases of Acute Radiation Syndrome (ARS) - Dose >8 Gy
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Dose Range in gray (Gy)
(What is gray?)
Data adapted from:
Diagnosis and Treatment of Radiation Injuries
(PDF - 202 KB)
(IAEA Safety Reports Series No. 2, Vienna 1998)

Timeline: >8 Gy


Acute Radiation Syndrome time phases resulting from greater than 8 Gy radiation expoure Start over

ARS time phases and approximate whole body dose from exposure: >8 Gy

Predominant
Manifest Illness
Subsyndromes		 Phases
Prodromal Latent Manifest Illness (Critical Phase) Recovery or Death
bar chart of subsyndrome severity of hematopoietic, gastrointestinal, and neurovascular subsyndromes
bar chart legend		 Vomiting
  • Onset: <10 minutes after exposure
  • Percent of victims who vomit at this dose: 100%
Diarrhea
  • Heavy
  • Onset: within minutes to hour after exposure
  • Percent of victims with diarrhea at this dose: ~100%
Headache
  • Severe
  • Onset: 1-2 hours after exposure
  • Percent of victims with headache at this dose: 80-90%
Level of consciousness
  • Loss of consciousness, may last seconds to minutes
  • Onset: seconds-minutes after exposure
  • Percent of victims with change in mental status at doses >50 Gy: 100%
Body temperature
  • High fever
  • Onset: < 1 hour after exposure
  • Percent of victims with fever at this dose: 100%
Medical response
  • Palliative treatment, especially for those with combined injury
  • Aggressive supportive care in selected cases
  • Palliative care for all others
 Duration
  • Patients move rapidly from prodrome to manifest illness, with short if any latency in between.
Epilation
  • Usually complete hair loss
Medical response
  • Palliative treatment, especially for those with combined injury
  • Aggressive supportive care in selected cases
 Onset
  • Immediate
Duration
  • Hours to months until recovery or death
Possible clinical effects
  • Anorexia
  • Fever
  • Malaise, weakness
  • Bleeding, infection
  • Epilation: hair is lost by day 10
  • Nausea, vomiting
  • Diarrhea: common by day 4-5; severe, profuse, bloody
  • Seizures, impaired level of consciousness
  • Hypotension
Medical response
  • Extremely aggressive supportive care for salvage in selected cases with good prognosis
  • Palliative care for all others
  • Psychological support
Lethality
  • Uniformly fatal within 1-2 weeks without aggressive supportive care
  • Palliative care for those unlikely to survive
 Recovery
  • Not expected without the most aggressive supportive care
Time to Death
  • Usually within hours to days of exposure