Acute radiation syndrome manifests in four stages: prodrome, latency, manifest illness, and either recovery or death. During the prodromal phase, patients usually experience nausea, vomiting, fatigue, and even loss of consciousness at higher doses. During the latent stage, patients can look and feel generally healthy for a few hours or even up to a few weeks. In the manifest illness stage, the symptoms depend on the amount of dose received and can last from hours to several months.