Causes and Prevention of Varicose and Spider Veins

Varicose Veins on a woman's legs
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Varicose veins are simply enlarged veins and spider veins are a smaller version of the same condition, though their appearance is different.

Women are more likely to develop this circulatory condition and, in the United States, up to 50 percent of women suffer from some form of vein disorder. It's estimated that 41 percent of all women will suffer from abnormal leg veins by the age of 50.

Though unsightly, varicose and spider veins don't usually require medical treatment.

They can cause dull discomfort and may get worse as you age, but severe pain is uncommon. Symptoms of discomfort may include:

  • Swelling in your feet and legs
  • Fatigued leg muscles and night cramps 
  • You may feel an itchy or burning sensation on the skin of your legs and ankles

Appearance and Location

Varicose veins have similar characteristics that you can see through your skin:

  • They're red or blue in color
  • They have the appearance of cords running just under your skin that may appear to be twisted and bulging

These veins pop-up on various parts of your body, including:

  • The backs of your calves
  • The inside of your legs
  • Anywhere from your groin to the ankle
  • In your vagina or around your anus, during pregnancy 

Spider veins look similar to varicose veins, but there are differences:

  • They are smaller
  • They are often red or sometimes blue in color
  • They are closer to your skin's surface
  • They look like a spider web with short, jagged lines
  • They cover either a very small or very large area of skin

When checking your body for spider veins, you can find them on your legs and face.


Your veins are part of your circulatory system. As the blood returns to the heart, healthy strong veins act as one-way valves to prevent the blood from flowing backward.

When veins weaken, some of the blood can leak backward, collect there, and then become congested or clogged. This causes the vein to abnormally enlarge, resulting in either varicose veins or spider veins.

Science has yet to uncover exactly what causes the one-way valves to weaken, but several factors make you more likely to develop them including:

  • Heredity, or being born with weak vein valves
  • Hormonal changes during puberty, pregnancy, and menopause, as well as taking estrogen, progesterone, and birth control pills
  • Pregnancy causes enlarged veins because your blood volume increases significantly 
  • Pregnancy makes your uterus larger and puts more pressure on the veins; you may see improvement within 3 months of delivery

Other factors that weaken vein valves and could contribute to the appearance of varicose and spider veins include:

  • Aging
  • Obesity
  • Leg injury 
  • Prolonged standing - commonly work-related for nurses, teacher, and food service workers


You can try to prevent varicose and spider veins by taking the following steps:

  • Exercise regularly to improve your leg strength, circulation, and vein strength
  • Control your weight to avoid placing too much pressure on your legs
  • Do not cross your legs when sitting and try to elevate your legs when resting
  • Do not stand for long periods of time
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Article Sources

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  • UCLA Gonda Venus Center: Symptoms and Diagnosis of Spider Veins
  • Varicose Veins and Spider Veins Fact Sheet (2012).