The terms used in describing the venous system are often unfamiliar and confusing. Hopefully the descriptions below will help you understand the subject matter more clearly.
Veins – general name given to the anatomic vascular structures that return blood to the heart. These structures contain one-way valves which begin to appear when the size of the vein gets to be > 40 micrometers in size.
Venule – general name given to the smaller veins. These veins range in size from post- capillary veins (the smallest) up to about 3mm. Venous structures > 3 mm are simply referred to as “veins”.
Varicose – a term meaning enlarged, dilated, and often tortuous veins located in the subcutaneous tissue and skin.
Varicose Veins – this has come to mean venous structures > 3mm in size located in the subcutaneous tissue.
Venulectasia – veins smaller than 3mm can become varicose and this term refers to them.
Spider Veins – small dilated intradermal veins of less than 1 mm in size. These are also called Telangiectasia (a particular form of venulectasia).
Reticular Veins – medium sized dilated interdermal veins measuring 1-3 mm in diameter. These are bluish in color and are varicose (dilated) and are not normal (another form of venulectasia). Not to be confused with normal visible bluish veins seen in people with thin or transparent skin.
Deep Venous System – this refers to the system of veins that lies deep to the connective tissue layer that surrounds the muscles. Most of the blood that returns to the heart travels through this system.
Superficial Venous System – this is the system of veins that lies superficial to the connective tissue layer that surrounds the muscles. Problems with this system are the cause of most of the treatable venous problems.
Perforating Veins – these are veins that connect the deep system to the superficial system. blood is directed normally to the deep system by these veins. When blood goes backwards (reflux), then problems can develop.