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Radiation Sickness

Medically reviewed by Last updated on Jan 5, 2023.

What is radiation sickness?

Radiation sickness develops when a person is exposed to high doses of radiation. It is also known as radiation toxicity, or acute radiation syndrome. A syndrome is a group of signs and symptoms that often happen together.

What are the stages of radiation sickness?

  • The prodromal stage occurs within minutes to days after exposure. Symptoms may last, off and on, from minutes to several days.
  • During the latent stage, you will look and feel well. This stage can last from hours to several weeks.
  • The manifest illness stage depends on the type of syndrome you have. This stage can last from hours to months.
  • Recovery or death depends on the amount of radiation exposure and the syndrome it caused. Lower doses of radiation increase your chance of recovery. Recovery can take up to 2 years. Higher doses of radiation become life-threatening.

What signs and symptoms may happen with bone marrow syndrome?

Bone marrow syndrome (hematopoietic syndrome) happens when bone marrow cells are damaged or destroyed. Infection and severe bleeding can occur.

  • In the prodromal stage, you may have loss of appetite, nausea, and vomiting that comes and goes. This stage starts 1 hour to 2 days after exposure.
  • In the latent stage, you will feel well for 1 to 6 weeks. Stem cells in your bone marrow die during this stage.
  • In the manifest illness stage, your blood cell counts drop. Bleeding, anemia, fever, and infection also happen.

What signs and symptoms may happen with gastrointestinal (GI) syndrome?

GI syndrome happens when cells in your GI tract are destroyed.

  • In the prodromal stage, you may have loss of appetite, severe nausea, and vomiting that comes and goes. You may also have severe cramps and liquid diarrhea.
  • In the latent stage, symptoms are mild. During this stage, cells in your intestines die.
  • In the manifest illness stage, you will feel sick. You will have loss of appetite and severe, often bloody, diarrhea. You may develop a fever, dehydration, and an electrolyte imbalance. Electrolytes include sodium and potassium.

What signs and symptoms may happen with cardiovascular (CV)/central nervous system (CNS) syndrome?

CV/CNS syndrome happens when your circulatory system or brain is affected. This syndrome causes your brain or blood vessels to swell.

  • In the prodromal stage, you may have severe nervousness and confusion. Severe nausea, vomiting, and watery diarrhea may come and go. You may also lose consciousness. This stage starts within minutes of exposure and can last for minutes to hours.
  • In the latent stage, some function may return. This stage lasts a few hours.
  • In the manifest illness stage, you may have severe nausea, vomiting, and watery diarrhea. You may also have convulsions or go into a coma.

What is cutaneous radiation syndrome?

Cutaneous (skin) radiation syndrome happens with many types of exposure to radiation. It can happen when skin becomes contaminated by radiation. Your skin will itch and become red and swollen within a few hours after exposure. The top layers of your skin will peel and the hair on your skin may fall out. Your skin will start to heal. Then your symptoms of itching, swelling, and redness will return. Complete healing may take up to a few years, depending on the dose of radiation.

How is radiation sickness treated?

Treatment goals include treating and preventing infections, keeping you hydrated, and treating injuries and burns. You may need medicines to help your bone marrow replace cells that have died. You may also need stem cell transfusions. Platelet transfusions may also be needed to help treat bleeding.

Where can I find more information?

  • Centers for Disease Control and Prevention (CDC)
    1600 Clifton Road
    Atlanta , GA 30333
    Phone: 1- 800 - 232-4636
    Web Address:

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