Imagine: you come to the clinic and the doctor says: “Give me some blood, urine and a chest x-ray, my dear.” You habitually handed over the jar of urine and fearlessly donated your finger to draw blood. A day or two later you looked for an answer - and now you are holding a form with incomprehensible numbers in your hands. Bring the form to the doctor, he takes a quick glance and says: “Everything is fine...” and pastes the piece of paper into the card. Now you can forget that just a day ago you were waiting with trepidation in your heart for the stiletto to pierce your ring finger and a ruby drop to fall onto a glass slide. But what was all this for? After all, judging by the doctor’s reaction, this is sheer nonsense. The book you are holding in your hands is not an ordinary guide to deciphering tests. Before you is a kind of guide who will teach you to navigate critical situations, understand what your doctor is talking about, and also allow you to meaningfully participate in your examination and treatment. Attention! This publication is not a manual for self-medication. A doctor's consultation is required.