Radiation sickness

Alternative names
Radiation poisoning

Radiation sickness is illness and symptoms resulting from excessive exposure to radiation, whether that exposure is accidental or intentional (as in radiation therapy). The term also includes the side effects of exposure to radiation.


Radiation is normally classified into ionizing and nonionizing types. Nonionizing radiation is familiar as light, radio waves, microwaves and radar - types of radiation which generally do not cause tissue damage.

Ionizing radiation is radiation that produces immediate chemical effects (ionization) on human tissue and includes X-rays, gamma rays, and particle bombardment (neutron beam, electron beam, protons, mesons, and others). This type of radiation can be used for medical testing and treatment, industrial testing, manufacturing, sterilization, weapons and weapons development, and many other uses.

Radiation sickness results when humans (or other animals) are exposed to excessive doses of ionizing radiation. Radiation exposure can occur as a single large exposure (acute), or a series of small exposures spread over time (chronic).

Radiation sickness is generally associated with acute exposure and has a characteristic set of symptoms that appear in an orderly fashion. Chronic exposure is usually associated with delayed medical problems such as cancer and premature aging, which may happen over a long period of time.

The degree of illness (acute radiation sickness) is dependent on the dose and the rate of exposure. For example:

  • Total body exposure of 100 roentgens causes radiation sickness.  
  • Total body exposure of 400 roentgens causes radiation sickness and death in half the individuals.  
  • 100,000 rads causes almost immediate unconsciousness and death within an hour

The severity of symptoms and illness depends on the type and amount of radiation, the duration of the exposure, and the body areas exposed. Symptoms of radiation sickness usually do not occur immediately following exposure.

Because it is difficult to determine the amount of radiation exposure from accidents, the best indications of the severity of the exposure are: the length of time between the exposure and the onset of symptoms, the severity of symptoms, and severity of changes in white blood cells.

Children who receive radiation treatments or who are accidentally exposed to radiation will be treated based on their symptoms and their blood cell counts. Frequent blood studies are necessary and require a small puncture through the skin into a vein to obtain blood samples.


The causes include:

  • Accidental exposure to high doses of radiation, such as in certain occupations  
  • Exposure to excessive radiation for medical treatments (may include excessively high doses, excessive time of exposure, or excessive body areas exposed)


  • nausea and Vomiting  
  • diarrhea  
  • Skin burns (redness, blistering)  
  • Weakness, fatigue, exhaustion, fainting  
  • Dehydration  
  • Inflammation of exposed areas (redness, tenderness, swelling, bleeding)  
  • Hair loss  
  • Ulceration of the oral mucosa  
  • Ulceration of the esophagus, stomach or intestines  
  • Vomiting blood  
  • Bloody stool  
  • Bleeding from the nose, mouth, gums, and rectum  
  • Bruising  
  • Sloughing of skin  
  • Open sores on the skin

Your doctor will advise you how best to treat these symptoms. He may prescribe medications to help reduce nausea, Vomiting, and pain. He may prescribe blood transfusions for anemia or antibiotics to prevent or fight infections.

First Aid

Only provide medical care if you have appropriate protective gear to prevent possible contamination:

  1. Check for adequate breathing and circulation.
  2. Start CPR if necessary.
  3. Remove clothing.
  4. Vigorously wash body with soap and water.
  5. Dry body and wrap with soft, clean blanket.
  6. Call for emergency medical assistance or transport to nearest emergency medical facility.

If symptoms occur during or after medical radiation treatments:

  1. Notify physician or seek medical treatment.
  2. Handle affected areas gently.
  3. Treat symptoms or illnesses as advised by physician.

Do Not

  • DO NOT remain in area where exposure occurred.  
  • DO NOT apply ointments to burned areas.  
  • DO NOT remain in contaminated clothing.  
  • DO NOT minimize the potential danger - radiation exposure is dangerous!  
  • DO NOT hesitate to seek emergency medical treatment.


  • Avoid unnecessary exposure to radiation sources.  
  • Always use “shields” over parts of the body not being treated or studied when receiving X-rays or radiation treatments.

Johns Hopkins patient information

Last revised: December 2, 2012
by Arthur A. Poghosian, M.D.

Medical Encyclopedia

  A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z | 0-9

All ArmMed Media material is provided for information only and is neither advice nor a substitute for proper medical care. Consult a qualified healthcare professional who understands your particular history for individual concerns.