Radiation sickness is illness and symptoms resulting from excessive exposure to radiation. Exposure may be accidental or intentional (as in radiation therapy).

There are two basic types of radiation: ionizing and nonionizing.

Nonionizing radiation comes in the form of light, radio waves, microwaves and radar. This kind of radiation usually does not cause tissue damage.

Ionizing radiation is radiation that produces immediate chemical effects on human tissue . X-rays, gamma rays, and particle bombardment (neutron beam, electron beam, protons, mesons, and others) give off ionizing radiation. This type of radiation can be used for medical testing and treatment, industrial and manufacturing purposes, weapons and weapons development, and more.

Radiation sickness results when humans (or other animals) are exposed to very large 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) depends on the dose and the rate of exposure. Exposure from x-rays or gamma rays is measured in units of roentgens. 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