Vascular Diseases
Vascular Diseases: Learn the Basics
Written byTriantafyllos Giannakopoulos MD, PhD, FEBVS, FACSMedically reviewed: 27 July 2026
Understand the vascular system and the main forms of vascular disease.
Arterial Diseases
Narrowings, blockages and aneurysms of the arteries that restrict the flow of oxygenated blood.
Learn MoreVenous Diseases
Varicose veins, deep vein thrombosis and chronic venous insufficiency of the lower limbs.
Learn MoreVascular Access
Creation and care of arteriovenous fistula for hemodialysis patients.
Learn MoreAesthetic Vascular Surgery
Treatment of telangiectasias and spider veins with excellent aesthetic results.
Learn MoreLymphatic Diseases
Management of lymphedema and lymphatic system disorders with modern methods.
Learn MoreUpper & Lower Limb Ulcers
Treatment of chronic, hard-to-heal ulcers of arterial, venous or mixed etiology.
Learn MoreThe Basics
The Circulatory System
The human body is dominated by a complex system of tubes (vessels) — known as the circulatory system — through which blood continuously circulates. The role of blood is to transport "fuel" (nutrients), oxygen essential for converting it into energy (calories), as well as the waste products of "combustion" (metabolites) for elimination.
The heart functions as a pump, sending blood through two circuits: Systemic Circulation (from the heart to the body and back) and Pulmonary Circulation (from the heart to the lungs and back). This system ensures that every cell in the body receives oxygen and nutrients, while metabolic waste products are removed.
Systemic Circulation
The pathway between the heart and the body, where blood carries oxygen and nutrients to every organ and tissue.
Pulmonary Circulation
The pathway between the heart and lungs, where blood is enriched with fresh oxygen and releases carbon dioxide.
Blood Flow
How Blood Circulation Works
The heart sends oxygen-poor venous blood to the lungs, where it is re-enriched with oxygen and waste gases are expelled. Then, the enriched blood returns from the lungs to the heart to continue its journey through the body. This shorter route is known as pulmonary circulation.
Rich in oxygen
Poor in oxygen
The Role of the Clotting Mechanism
The Role of the Clotting Mechanism
The blood clotting mechanism, by forming a clot (solid blood), ensures vessel integrity — prevents and limits bleeding. It is activated mainly in three situations, known as Virchow's triad, who was the first to describe it.
In several cases of patients with repeated thrombotic episodes — or with relatives who present thromboses — genetic testing reveals hereditary hyperfunction of the clotting mechanism (Thrombophilia), requiring prophylaxis with anticoagulant therapy.
Virchow's Triad
Low Flow
Low blood flow.
Vessel Injury
Injury to the vessels.
Hyperfunction
Hyperfunction of the clotting mechanism.
Thrombophilia: hereditary hyperfunction of the clotting mechanism requiring personalized anticoagulant prophylaxis.
Forms of Disease
Vascular Disease
Vascular disease manifests in three main forms, while combinations of two or three forms may coexist simultaneously in the same disease or the same patient.
Reduction of Arterial Supply (Ischemia)
The arteries supplying blood to an area of the body do not function adequately, with arterial blood decreasing and thus reducing both oxygen and energy in that specific area.
Symptoms are due to dysfunction of the area and are more intense the less blood reaches the tissues. The damage may be permanent or not, depending on the sensitivity of the area to oxygen deprivation (neural tissue is the most sensitive, especially that of the brain) and the duration of blood deprivation.
Reduction of Venous Drainage (Venous Stasis)
The veins through which venous blood drains from an area (oxygen-poor, rich in metabolic toxins) do not function adequately — they thrombose or become insufficient.
This condition causes pooling/stasis of venous blood in the affected area, with symptoms of heaviness, edema (swelling), warmth, redness and pain. In the case of a clot, the vein may be palpable like a cord, firm and painful.
Rupture of Vessel Wall & Hemorrhage
The artery or vein undergoes rupture or erosion from pathological or traumatic causes (e.g. aneurysm rupture) and blood exits the circulation, either inside or outside the body.
When bleeding originates from arteries — which carry blood at higher pressure than veins — it is more dangerous than venous bleeding and, if not treated promptly, can threaten the patient's life.
Need Help?
Contact us for more information about vascular diseases and available treatments.
The content of this website is intended exclusively for general information and educational purposes and does not substitute professional medical advice, diagnosis, or treatment. Read our full Terms of Service
In case of a medical emergency, call 112 (the European emergency number) or go to the nearest emergency department.