Occupational diseases arise as a result of exposure to the adverse factors of the working environment. Clinical manifestations often do not have specific symptoms, and only information about the working conditions of the ill can establish the belonging of the revealed pathology to the category of occupational diseases. Only some of them are characterized by a special symptom complex, due to peculiar radiographic, functional, hematological and biochemical changes.

There is no generally accepted classification of occupational diseases. The most recognized classification was based on the etiological principle. Proceeding from this, five groups of occupational diseases are distinguished: 1) caused by the action of chemical factors (acute and chronic intoxications, as well as their consequences, which occur with isolated or combined lesions of various organs and systems); 2) caused by dust (pneumoconiosis-silicosis, silicates, metalloconiosis, pneumoconiosis of electric welders and gas cutters, grinders, abrasives, etc.); 3) caused by physical factors: vibration disease; Diseases associated with exposure to contact ultrasound - autonomic polyneuritis; Hearing loss by type of cochlear neuritis - noise disease; Diseases associated with exposure to electromagnetic radiation and scattered laser radiation; radiation sickness; Diseases associated with changes in atmospheric pressure - decompression sickness, acute hypoxia; Diseases caused by unfavorable meteorological conditions-overheating, convulsive disease, obliterating endarteritis, vegetative-sensitive polyneuritis; 4) caused by overexertion: diseases of peripheral nerves and muscle-neuritis, radiculopineuritis, vegetative sensory polyneuritis, cervico-brachial plexitis, vogetomyocytes, myofasciitis; Diseases of the musculoskeletal system - chronic tendovaginitis, stenosing ligamentitis, bursitis, ericondylitis of the shoulder, deforming arthrosis; Coordinating neuroses - writing spasm, other forms of functional dyskinesia; Diseases of the vocal apparatus - fossil and organ of vision - asthenopia and myopia; 5) caused by the action of biological factors: infectious and parasitic - tuberculosis, brucellosis, sap, anthrax, dysbacteriosis, candidiasis of the skin and mucous membranes, visceral candidiasis, and others.

Beyond this etiological systematics are occupational allergic diseases (conjunctivitis, upper respiratory tract diseases, bronchial asthma, dermatitis, eczema) and oncological diseases (skin, bladder, liver, upper respiratory tract tumors).

There are also acute and chronic occupational diseases. Acute occupational disease (intoxication) occurs suddenly, after a single exposure (for not more than one shift) to relatively high concentrations of chemicals in the air of the work area, as well as levels and doses of other unfavorable factors. Chronic occupational disease occurs as a result of prolonged systematic exposure to the body of adverse factors.

For the proper diagnosis of occupational disease, it is especially important to carefully study the sanitary and hygienic working conditions, the patient's anamnesis, its "professional route", which includes all the types of work that have been performed since the beginning of work. Some occupational diseases, such as silicosis, berylliosis, asbestosis, bladder papilloma, can be detected many years after the termination of exposure to industrial hazards. The reliability of the diagnosis is ensured by careful differentiation of the observed disease with non-occupational etiology similar in clinical symptomatology. A definite help in confirming the diagnosis is the detection in the biological media of the chemical substance that caused the disease, or its derivatives. In a number of cases, only a dynamic observation of the patient over a long period of time makes it possible to finally resolve the issue of the relationship between the disease and the profession.

The main document used to determine the affiliation of this disease to the number of professionals is the "List of occupational diseases" with instructions for its use, approved by the Ministry of Health of the USSR and the All-Union Central Council of Trade Unions.

Among the most important preventive measures for the protection of labor and the prevention of occupational diseases are preliminary (upon admission to work) and periodic inspections of workers exposed to harmful and unfavorable working conditions.