Objective: To improve the results of surgical treatment of phlegmon of the upper limb by developing a method for diagnosing and treating compartment syndrome. For the complex treatment of patients with phlegmon of the upper limb (shoulder and forearm), an individual algorithm was developed, while one of the key factors for determining treatment tactics was tissue pressure. In the course of making the calculation according to the formula, the obtained indicators served as the basis for determining the tactics of treating the compartment syndrome, namely its drug therapy or surgical resolution (fasciotomy). The study involved 134 patients with deep intermuscular phlegmon of the shoulder and forearm, divided into two groups: the first group included 62 patients who were treated using known technologies. In group II (72 patients), the developed diagnostic and therapeutic algorithm was used, taking into account the severity of tissue hypertension and compartment syndrome. The proposed algorithm for the diagnosis and treatment of phlegmon of the shoulder and forearm, protected by RF patents for inventions No. 2587972, No. 2695367, No. 2755388, has improved the results of complex treatment and reduced the time of postoperative rehabilitation of patients.