The handbook outlines differential diagnosis for 124 syndromes or symptoms of internal organ diseases, including those that are rarely encountered. The information provided in the handbook about basic pharmacotherapy will assist the physician in the task of prescribing comprehensive personalized therapy. Basic pharmacotherapy (BPT) includes groups of medications and individual drugs using predominantly international names without specifying dosages, treatment regimens, indications, and contraindications. The handbook consists of two volumes, which include descriptions of 124 syndromes. The first volume provides a list of abbreviations, and at the end of the second volume, subject and eponymous indexes are given. We hope that the 4th, updated edition of the handbook will be useful for physicians of various specialties, especially therapists and general practitioners (family medicine) in solving complex diagnostic tasks and selecting personalized therapy. Over the years of communication with the readers of the handbooks, we have confirmed that they serve as a teaching aid for students, interns, and clinical residents. In creating these handbooks, we sought to fulfill one of the mandates of S. P. Botkin (1867): "…The clinician-teacher sets as his primary task the transmission of the method, guiding which the young practitioner would subsequently be able to independently apply his theoretical and medical knowledge to individual patients whom he will encounter in his medical practice". The necessity to create a revised handbook is explained by the complication of diagnosis due to polymorbidity, blurring, and atypical course of diseases, the expansion of the list of so-called rare diseases, and the influence of polypharmacy on the course of diseases. Furthermore, it is necessary to take into account the emergence of new methods of diagnosis and treatment. In this regard, each reissue of the handbook is accompanied by an update of its content. The basic principles of conducting differential diagnosis remain unchanged. All this requires from the therapist not only a significant volume of factual knowledge but also the ability to think clinically, compare numerous clinical, instrumental, and laboratory data during diagnosis and treatment, formulating an individual, sometimes very complex, diagnosis, and prescribing personalized therapy. The use of this handbook by doctors of almost all specialties will not only facilitate the differential diagnostic and treatment process but will also help to form a style of clinical thinking inherent to the Botkin school of therapists. Compilers: K. N. Kryakunov, N. N. Lukashevskaya.
