Radiation sickness, unspecified, initial encounter

This code signifies an acute illness resulting from exposure to high levels of ionizing radiation, where the specific type or dose of radiation is not documented. Symptoms can range from nausea and vomiting to more severe manifestations like bone marrow suppression and neurological damage, depending on the exposure level.

Apply this code for patients presenting with signs and symptoms consistent with radiation sickness following an initial, undocumented exposure to radiation. This is appropriate when the specific source, type, or dose of radiation is unknown or not yet determined. It is used for the first encounter related to this specific radiation exposure event.

• Only use this code for the initial encounter of a radiation sickness event. Subsequent encounters would utilize a different seventh character.
• Ensure documentation supports an unspecified nature of the radiation exposure; if the type or source is known, a more specific code should be chosen.
• Always sequence this code as the primary diagnosis when radiation sickness is the reason for the encounter.