What Causes Spider Veins?

What usually causes spider veins?  Can crossing your legs give you spider veins?

Doctor Answers 9

Spider Veins - Purely Cosmetic ?

Varicose veins are enlarged veins that bulge through the skin and may appear as blue or purple knot-like cords. Varicose veins can occur anywhere in the body, but are more commonly found in the lower extremities. Spider veins, also known as telangiectasias are smaller than varicose veins and often look like a sunburst or "spider web." They are red or blue in color and are commonly found on the face and legs.

The most important consideration for a patient is to recognize whether spider veins are associated with venous reflux disease. If they are associated with venous reflux disease, then this has to be treated before cosmetic procedures such as sclerotherapy or topical lasers are used to obliterate these spider veins.

Venous reflux disease is currently treated in the office setting with the VNUS Closure procedure or endovenous laser procedures (EVLT, ELVeS, etc.). Alternatively, some surgeons still perform ligation and stripping procedures. Once these procedures are done, then it is ideal to follow this with topical transdermal laser treatment of the spider veins. It is more likely for spider veins to recur if underlying venous reflux disease is not addressed.

Another important point is that venous reflux disease is associated with symptoms in the legs, whereas pure spider veins are unlikely to be associated with symptoms in the leg - such as aching, pain, heaviness, tiredness, fatigue, itching, burning, cramping, throbbing, restlessness of the legs or swelling in the ankles or legs.

Venous reflux disease can be diagnosed with special maneuvers on physical examination. More specifically, it is confirmed and documented with Duplex venous ultrasonography.

In summary, be wary of just walking into any clinic to get laser treatments done for spider veins. Make sure that you are evaluated and venous reflux disease is excluded before you proceed with topical laser therapy for spider veins. This will save you the heartache of having repeat laser treatments which are costly and the dissatisfaction that goes with having repeated cosmetic procedures that are unnecessary.

There are several causes for spider veins

Any build up of pressure can induce spider veins.

  • Blockage from above by bad valves in the deep system of veins
  • Crossing legs
  • Standing immobile for long periods
  • Impact, including, running

...can all produce spider veins. Other factors are inheritance and hormones (including the elevation of estrogens in pregnancy).

Ronald Shelton, MD
Manhattan Dermatologic Surgeon
5.0 out of 5 stars 33 reviews

Cause of Spider Veins

Just the sheer force of gravity on the legs may trigger varicose and spider veins over time. Remember: these veins, with the help of valves inside the veins, have to push blood up to the heart—a task that’s hard due to the pressure of body weight and the force of gravity. If these one-way valves become weak, blood can leak back into the veins, triggering varicose and spider veins.
Sun exposure, hormonal changes (as during pregnancy or menopause—or if you’re taking birth control pills or other hormones), certain skin conditions like rosacea, obesity (which puts greater pressure on the veins in the legs), injury to that area, and aging can all trigger these broken veins to appear. Regularly crossing your legs while sitting can also put pressure on your veins—triggering varicose and spider veins over time.
Genetics also plays a role: if spider or varicose veins runs in your family, you’re more likely to develop them, too. Plus, if you’re fair-skinned, you also have a higher likelihood of developing spider veins, particularly on the nose and cheeks.

Dennis Gross, MD
New York Dermatologist
4.5 out of 5 stars 8 reviews

Causes from Increased Blood-Flow

Techinically, crossing your legs can in fact lead to a higher incidence of spider veins (dilated vessels), but it’s not the only thing. Any activity that increases flood flow to the legs can account for dilated blood vessels that enlarge to accommodate additional blood volume. Long days on your feet? That’ll do it. Pregnancy? With increased volume of blood and an enlarged uterus pressing against the inferior vena cava. That’ll do it too. Increased exercise actually has the opposite effect by mobilizing blood volume from the legs back into the general circulation.

Bobby Buka, MD
New York Dermatologist
5.0 out of 5 stars 7 reviews

Genetics and multiple other factors.

Spider veins get their name because they look like little spider legs.  They can be red or blue and can occur almost anywhere in the body but primarily on the legs and face. A bunch of spider veins together is call telangiectasia.  The chief cause of spider veins is usually a hereditary factor.  Other causes include sun exposure, aging, pregnancy and even trauma.  Debateable causes include wearing constricting garments and crossing the legs.  In many instances, spider veins like varicose veins could be due to a weakness in the valves of the saphenous system.  This is caused reflux and can be diagnosed by a venous reflux exam.  In those patients with extensive spider veins and/or blue feeding(reticular) veins a venous reflux ultrasound would be of benefit.

John Landi, MD
Naples General Surgeon
5.0 out of 5 stars 4 reviews

Spider Veins, Causes and Treatments

Spider veins are small enlarged superficial blood vessels that appear at the skin surface as red or blue. Spider veins commonly occur on the legs. These dilated blood vessels may be short, unconnected hair-like lines, or connected in a "sunburst" pattern. Sometimes, spider veins occur in a small area and aren't very noticeable. Other times, they can cover a large area of skin and be very unattractive. Larger dilated blood vessels (called reticular veins) may appear blue or green through the skin’s surface and often occur along with spider veins.

Physiologically speaking, leg veins are a result of valvular insufficiency of the veins in the legs. Causes of valvular insufficiency can include inheritance pattierns, hormones, standing immobile for extended periods of time, crossing the legs for extended periods of time, excessive weight, pregnancy or trauma.

Sclerotherapy is injection therapy for spider veins and larger reticular veins of the leg. The procedure is simple. Veins are injected with a solution which causes the veins to collapse and fade from view. The number of treatments depends on the amount and severity of your condition and the results that you hope to achieve.

Causes of spider veins

The root cause of spider veins are genetic factors involving poor circulation. Those that have spider veins generally have a genetic predisposition to have a less than perfect valve structure in the primary leg veins. As we age, the valves that prevent the backflow of blood (away from the heart) can deteriorate, causing a buildup of blood in the lower legs. When this happens, pressure increases at the extremities and spider veins (or varicose veins) can develop.

There are other non-genetic reasons for a buildup of blood and pressure at the extremities including pregnancy, temporary or permanent weight gain and fluid buildup that may not be genetically related but still capable of causing spider veins.

Harold J. Kaplan, MD
Los Angeles Facial Plastic Surgeon
5.0 out of 5 stars 6 reviews

Exclude venous problems

Spider veins are small superficial veins that are detected in different body areas. Our patients seek different line of treatments for these veins from laser to light therapy etc..

When we discover these veins on the lower extremity, more clinical exam is needed to exclude deep venous problems e.g incompetent valves or deep system involvement.

Hisham Seify, MD, PhD, FACS
Orange County Plastic Surgeon
5.0 out of 5 stars 17 reviews

Small vessels

Spider veins are small superficial blood vessels that appear purple, red or blue just underneath the skin. They commonly appear on the legs, but occasionally also on the face. These dilated blood vessels may look like a spider web or tree with the branches. They can occur in a small area, or cover a large area of the skin and be very unattractive. Patients often seek treatment for spider veins because of cosmetic concerns. Spider veins can be caused by venous insufficiency. Additional causes of spider veins include hormone changes, sun exposure and inherited related factors. The most common treatment for spider veins is sclerotherapy. That involves injection of liquid agent into the vein to become less visible.

These answers are for educational purposes and should not be relied upon as a substitute for medical advice you may receive from your physician. If you have a medical emergency, please call 911. These answers do not constitute or initiate a patient/doctor relationship.