In some healthcare systems, it is common that patients address laboratory test centers directly without a doctor's referral. Russia is one of such countries with about 28% of the patients going directly to the laboratory test center for diagnostics. This leads to a situation when patients are not supported by healthcare professionals in the interpretation of test results. Interpretation of test results is a resource-consuming task that will delay the results and increase costs of each test. However, this can be done by computer-based decision support systems that have proved to solve such tasks efficiently. So, the design and implementation of a decision support system that would generate reports for the patients who referred to a test center without a doctor's referral can increase motivation and support patients to make better informed decisions. The goal of this study is to implement a decision support system for patients. We developed a clinical decision support system for the patients that solves a classification problem by relating a vector of test results to a set of diagnoses and find a set of recommendations associated with every diagnosis from this set.