Varicose veins and venous insufficiency
- Lesion
When pressure in a vein stays high, the vein stretches, twists and its valves fail. It happens in the legs, oesophagus, anus and scrotum.
What it is
Varicose veins are abnormally dilated, tortuous veins produced by prolonged high intraluminal pressure and loss of wall support. In the legs, upright posture, valve incompetence, obesity, pregnancy and family history lead to superficial varicosities and chronic venous insufficiency with edema, stasis dermatitis and ulcers. The same process at portocaval anastomoses in portal hypertension produces oesophageal varices, haemorrhoids (anorectal veins) and caput medusae; in the pampiniform plexus it produces a varicocele.
Structure
- Gross: dilated, tortuous, elongated veins with nodular swellings; valves deformed.
- Microscopy: alternating thinning and thickening of the wall from smooth-muscle hypertrophy and intimal fibrosis; elastic tissue degeneration; frequent mural thrombi.
Step by step
- Pressure rises in a vein (gravity when standing, pregnancy, obesity, portal hypertension, obstruction).
- The wall stretches and the valve cusps no longer meet.
- Blood refluxes, raising pressure further in the segment below.
- The wall remodels: it thins in some places, thickens with fibrosis in others, and the vein twists.
- Stasis leads to edema, thrombosis and poor nutrition of the skin and tissues.
Where varicosities form and why
| Site | Cause of high pressure | Main complication |
|---|---|---|
| Superficial leg veins | Valve incompetence with upright posture, pregnancy, obesity | Venous stasis dermatitis and ulcers |
| Oesophageal varices | Portal hypertension (cirrhosis) | Massive upper gastrointestinal bleeding |
| Anorectal veins (haemorrhoids) | Straining, pregnancy, portal hypertension | Bleeding, thrombosis, prolapse |
| Pampiniform plexus (varicocele) | Left testicular vein draining at a right angle into the renal vein; valve failure | Pain, reduced fertility |
Clinical notes
- Stasis ulcers above the medial malleolus heal slowly because of edema and poor tissue oxygenation.
- A new right-sided or sudden left varicocele in an adult may signal obstruction of the renal vein by a tumour.
Test yourself
Think of the answer, then tap the question to see it.
Why do superficial leg varicose veins rarely cause pulmonary embolism?
Thrombi in superficial veins seldom embolise; pulmonary emboli come mainly from deep leg and pelvic veins.
What causes the brown skin pigmentation of chronic venous insufficiency?
Hemosiderin from red cells that leak into the tissue under high venous pressure.
Why are varicoceles more common on the left?
The left testicular vein drains at a right angle into the left renal vein, giving higher pressure and more reflux than the right.
Elsewhere in DurgiPedia
- Blood vessels: artery, vein and capillary layers
- Varicose veins: the Trendelenburg (Brodie–Trendelenburg) test
Connections
Educational content on the mechanisms of disease; not a diagnostic or treatment guide and no substitute for a health professional's advice. No doses are given.
Sources: Varicose Veins | Spider Veins | MedlinePlus (MedlinePlus, US National Library of Medicine, 2025); Venous Insufficiency (StatPearls (NCBI Bookshelf), 2025); Portal Hypertension (StatPearls (NCBI Bookshelf), 2025).
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Representative model, for educational purposes only.