Acute and chronic radiation sickness have peculiar mechanisms of development. This excludes the transition of the disease from one form to another.
Acute radiation sickness manifests itself as syndromes,dependent on the dose of external irradiation, which determines the detection of various violations. The development of clinical symptoms depends on the type of radiation with certain specific features. It is with them, mainly, the differences of the damaging effect on systems and organs are related.
Acute radiation sickness with a typical course is divided into four degrees of severity.
The mild degree, as a rule, proceeds without the especially expressed symptoms. In such cases, one should speak about radiation injury.
The severe degree is followed for a long timeproceeding (during one or two years) by restoration processes. In cases where persistent changes persist, it is said that acute radiation sickness has consequences.
The time of appearance of the first phase of the general reactionprimary character for radiation damage depends on the dose and can be calculated in minutes or hours. Characteristic signs of the reaction include nausea, a feeling in the mouth of dryness or bitterness, vomiting, rapid fatigue, headache, drowsiness, weakness.
There are also shock-like conditions thataccompanied by a decrease in blood pressure, loss of consciousness. Diarrhea and fever may occur. Such symptoms, as a rule, are observed with radiation damage in doses higher than 10 Gy.
Disease in the first phase with radiation damagemore than 3 Gy is accompanied by some biochemical shifts. These include a decrease in serum albumin levels, an increase in the glucose level in the blood, accompanied by a change in the sugar curve. In more severe cases, moderate bilirubinemia of a transient nature is noted. In turn, this indicates a violation in the liver of metabolic processes.
The second phase of the disease is characterized asa period of false clinical well-being. This, the so-called latent or latent phase, is observed after the disappearance of the primary signs of the reaction after three to four days after radiation damage. This phase continues for fourteen to thirty-two days. This period is accompanied by an improvement in the well-being of patients with a certain lability of blood pressure and pulse rate. With radiation damage in a dose of more than 10 Gy, acute radiation sickness from the first phase passes right into the third phase. Completion of the latent phase is accompanied by a sharp deterioration of the patients, resembling a septic state. For this condition, manifestations of increasing general weakness, fever, frequent heart rate, lowering blood pressure are characteristic. There are pronounced puffiness and bleeding gums. There are also lesions of the oral mucosa and the gastrointestinal tract, which are manifested by numerous necrotic ulcers.
The third phase is accompanied by a pronouncedclinical symptoms. At the same time, the onset time and intensity level of a number of syndromes are related to the dose of radiation received. A prolonged third phase is seven to twenty days.
The defeat of the circulatory system during this phaseis dominant. Together with it, suppression of immunity, development of autointoxications and infections, hemorrhagic symptom is observed. In this case, the disease is not characterized as a chronic radiation sickness.
The fourth phase is the direct recovery phase and begins with an improvement in the state and normalization of the temperature.
If the disease was severe,there is a long-term persistence of the pastosity of the limbs and face, tarnishing brittleness, dryness of the remaining hair. On the hair loss site, hair growth resumes three or four months after radiation damage.
