Internal diseases is the broadest specialty in medicine. It covers lesions of lungs, heart, gastrointestinal tract, urogenital system, rheumatic lesions. The human organism is integral and all organs and system function at permanent interaction. The physicians-internists, making a thorough examination of the patient by systems and using, if necessary, extra examinations, diagnose and treat the relevant lesion. Due to its comprehensiveness, the specialty of Internal diseases is sub-divided into number of close specialties like gastroenterology, pulmology, etc.