In modern diagnostics and treatment of vein diseases, sonography is a basic examination method that allows us to accurately determine the correct diagnosis and choose the right treatment method. It is a painless and non-invasive procedure that allows the doctor to see the venous system in real time, distinguish between individual veins (deep, superficial, connectors) and selectively check them, or detect neurovascular and arteriovenous conflict. Blood flow analysis shows the exact location of non-functional valves. It is also possible to determine the size of the veins, their location, and individual anatomy, which allows for the most accurate treatment planning.