Phlebology is a medical speciality that is concerned with venous issues including the diagnosis and treatment of disorders of the veins. A medical specialist in this field is known as a phlebologist. The specialty of phlebology has developed to enable physicians sharing an interest in venous disease and health to share knowledge and experience despite being trained in a variety of backgrounds such as dermatology, vascular surgery, haematology, interventional radiology or general medicine. Diagnostic techniques used include the patient's history and physical examination, venous imaging techniques in particular vascular ultrasound and laboratory evaluation related to venous thromboembolism. The American Medical Association and the American Osteopathic Association have added phlebology to their list of self-designated practice specialties.

A significant part of a phlebologist's work is involved with the treatment of superficial venous disease, frequently of the leg. Conditions often treated include venous stasis ulcers, varicose veins and spider veins (telangiectasia). Other conditions managed by phlebologists include deep venous thrombosis (DVT), superficial thrombophlebitis, and venous malformations.

The Union Internationale de Phlébologie (UIP) is committed to the global expansion of knowledge in the growing field of phlebology and aims to facilitate the advancement of science by encouraging research and education in all aspects of venous and lymphatic disease. The Union is ultimately aiming to facilitate comprehensive training programs in its member countries with the ultimate aim of establishing phlebology as a recognised  multidisciplinary specialty of medicine.  

The Australasian College of Phlebology (ACP) founded in 1993 has established a comprehensive four year training program in phlebology incorporating an online modular curriculum that complements supervised clinical training.

The American Medical Association added phlebology to their list of self-designated practice specialties in 2005. In 2007 the American Board of Phlebology (ABPh), subsequently known as the American Board of Venous & Lymphatic Medicine (ABVLM), was established to improve the standards of phlebologists and the quality of their patient care by establishing a certification examination, as well as requiring maintenance of certification. Although As of 2017^[update] not a Member Board of the American Board of Medical Specialties (ABMS), the American Board of Venous & Lymphatic Medicine uses a certification exam based on ABMS standards.

The American Vein and Lymphatic Society (AVLS), formerly the American College of Phlebology (ACP) one of the largest medical societies in the world for physicians and allied health professionals working in the field of phlebology, has 2000 members. The AVLS encourages education and training to improve the standards of medical practitioners and the quality of patient care.

The American Venous Forum (AVF) is a medical society for physicians and allied health professionals dedicated to improving the care of patients with venous and lymphatic disease. The majority of its members manage the entire spectrum of venous and lymphatic diseases – from varicose veins to congenital abnormalities to deep vein thrombosis to chronic venous diseases. Founded in 1987, the AVF encourages research, clinical innovation, hands-on education, data collection and patient outreach.

Regulatory requirements for phlebology certification are different in Europe and the US.