Radiation sickness occurs as a result of excessive exposure to radiation. It is the damage to the body due to a very large dose of radiation that is often received over a short period of time (acute). Radiation sickness is also known as radiation poisoning, acute radiation syndrome, or acute radiation sickness. Exposure to radiation may be accidental or intentional (such as in radiation therapy). Radiation has two basic types: nonionizing and ionizing. Nonionizing radiation does not usually cause tissue damage. It comes in the form of microwaves, radar, light, and radio waves. Ionizing radiation produces instant effects on human tissues. Gamma rays, X-rays, and particle bombardment emit ionizing radiation. Ionizing radiation is used for weapons and weapons development, industrial and manufacturing purposes and medical testing and treatment.
Mental retardation, cataracts, or cancer can occur when a person is exposed to large amounts of radiation. Usually, a person will not get sick with just one exposure to x-ray. As the number of exposure to x-ray radiation increases, so does the risk. It needs a large amount of x-ray radiation to kill a cell but it can damage the DNA and may cause health problems. Radiation exposure can happen as a single large dose (acute) or as a series of small exposures spread over time (chronic).
The unit of measurement for the absorbed dose of radiation is called gray (Gy). A type of x-ray exam such as the whole-body computerized tomography (CT) scan has an average whole-body dose of about 0.012 Gy. In order for signs and symptoms of radiation sickness to appear, the absorbed doses to the whole body must be at least 1 Gy. Absorbed dose of radiation that is greater than 8 Gy are usually not treated successfully. It can lead to the patient’s death within two days to 2 or 3 weeks. It will depend on the duration of the exposure.
A patient who has treatable radiation sickness will experience nausea and vomiting as initial signs and symptoms. After its initial signs and symptoms, the patient will have a few days of no visible signs of the illness. This stage comes first before the onset of signs and symptoms of a more serious illness. An acute absorbed dosage of 1 to 2 Gy may result in a mild radiation sickness. Its signs and symptoms may include: weakness, fatigue, headache, and nausea and vomiting within 24 to 48 hours. Moderate radiation sickness may be experienced by a person who has an acute absorbed dose of 2 to 3.5 Gy. The patient may experience: poor wound healing; fever; hair loss; vomiting blood; infections; bloody stool; nausea and vomiting within 12 to 24 hours; and any of the signs and symptoms for a lower absorbed dose.
Severe radiation sickness can be experienced when the absorbed dose is 3.5 to 5.5 Gy. Signs and symptoms include: diarrhea; high fever; nausea and vomiting less than one hour from exposure; and any signs and symptoms associated with a lower absorbed dose. Very severe radiation sickness will be experienced by a person with an absorbed dose greater than 5.5 to 8 Gy. This type of radiation sickness is often fatal. The patient will experience nausea and vomiting less than 30 minutes from exposure, low blood pressure, disorientation, dizziness, and any signs and symptoms for a lower absorbed dose.
