Which phase of Acute Radiation Syndrome is defined by the initial symptoms such as nausea, vomiting, and malaise?

• A. Prodromal Phase
• B. Latent Phase
• C. Manifest Illness Phase
• D. Recovery or Death Phase

Answer: (A)

Acute Radiation Syndrome unfolds in stages, and the first signs appear during the prodromal phase. This early stage is defined by the initial symptoms—nausea, vomiting, and malaise—that typically appear within hours of exposure and may last a short period depending on the dose. After the prodromal phase, a symptom-free latent interval may occur, and if the dose is high enough, the illness progresses to the manifest illness phase with more pronounced and varied symptoms. The final outcome, recovery or death, follows after the illness stage. So those initial nausea, vomiting, and malaise symptoms are the hallmark of the prodromal phase.