Do You Know What Causes Spider Veins?

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For many patients, spider veins are a cosmetic issue.  When these small red or blue veins form a cluster like a spider’s web, they can undermine self-confidence.  Understanding why they develop is important for patients considering treatment.

Spider Vein Basics

Between 50 and 55 percent of U.S. females and 40 to 45 percent of males have some type of problem with their veins, according to  Often, it is a spider vein issue.

In many cases, a vein specialist, or vascular surgeon, considers a spider vein a type of varicose vein.  However, some experts believe the two are distinct types of vessels.  A spider vein usually lies closer to the surface of a patient’s skin than a varicose vein and is significantly smaller.  A varicose vein has a distinctive ropelike appearance.

A spider vein is most likely to appear on a leg or on the face.  A varicose vein most often develops on a leg.  Either type occurs as the result of pooling blood that stretches a vein, causing it to bulge.  Vein treatment choices for spider-like vessels include sclerotherapy and laser therapy, the Mayo Clinic reports.

A Vein Doctor Cites Causes

Many patients wonder how they developed a spider vein problem.  These are the most frequent causes, according to UCLA Health:

  • Genetic factors:  Women are more at risk for spider and varicose veins than men.  A majority of women with spider-like vessels have close female relatives with the same condition.  Genetics might also determine at which age abnormal vessels appear.
  • Being pregnant:  Fluctuating progesterone and estrogen can cause walls of veins and valves to soften.  This makes vessels more likely to stretch and enlarge with added pressure.  Sometimes a spider vein problem persists after pregnancy.  With some patients, these vessels disappear after delivery but appear again later.
  • Prolonged sitting and standing:  They cause pressure to amass in leg veins.  Since calf muscles are not in use, they cannot help push blood toward the heart.  It pools, increasing pressure in veins.  Vein walls enlarge, potentially resulting in a a spider vein.
  • Injury:  Trauma from events like a car accident, a sports mishap, or a broken bone can cause a spider vein problem.  Bruising breaks veins under the skin.  This can cause inflammation resulting in enlarged veins.
  • Issues with other veins:  Blow-outs from varicose veins are more common in males than in females.  The resulting elevated pressure causes adjoining vessels to stretch, get bigger, and change color.

Vein doctors also often cite being obese or overweight as a risk factor for these abnormal veins.  Exposure to the sun sometimes results in spider vein development on the nose or the cheeks.  What is important to remember is that all the factors mentioned do not necessarily contribute equally to the results in different patients.