Spider veins are blood vessels located just beneath the skin surface that grow larger and appear red or blue when they weaken and become clogged. They most often appear in “sunburst” patterns on the face and legs, but also can affect other areas of the body.

Spider veins appear in both sexes, but are more common in women. More than 40 percent of women will suffer from abnormal leg veins by the time they are in their 50s, according to the U.S. Department of Health and Human Services. Spider veins are usually considered medically harmless, although they may cause a dull, aching sensation after prolonged standing. In rare cases, they may be associated with more serious health conditions such as liver or venous disease.

A number of different therapies are available to treat spider veins. These include sclerotherapy, a procedure in which a dermatologic surgeon injects a solution into the spider vein. The vein closes up or collapses, turns into scar tissue and is absorbed by the body over a period of months.

Spider veins form when a small group of blood vessels close to the skin dilate, or become larger. Also known as telangiectasias or sunburst varicosities, they are red or blue in appearance and can show up anywhere on the body, but most often appear on the face and legs. Although usually medically harmless, they may cause a dull, aching sensation after prolonged standing. In rare cases, they may be associated with more serious health conditions such as liver disease or severe venous disease.   

Veins are an essential part of the cardiovascular system, which transports oxygen and nutrients throughout the body.  The heart pumps blood rich in oxygen and nutrients through arteries to the body. Veins transport depleted blood back to the heart, which pumps the blood through the lungs to pick up fresh oxygen.

Within the veins, valves keep blood moving back toward the heart. When these valves weaken, some of the blood can leak backwards, causing them to become clogged. The congestion will cause the vein to enlarge into a spider vein. Larger dilated veins may become raised above the skin surface. These are called varicose veins and are similar to spider veins. They may be treated in conjunction with nearby spider veins.

Roughly 60 percent of all American women and men will develop some type of vein disorder, according to the U.S. Department of Health and Human Services, but women are more affected. More than 40 percent of women will suffer from abnormal leg veins by the time they are in their 50s.

The age at which spider veins begin to occur varies from patient to patient. They may develop during the teen years in some patients, but in others they may not appear until the person reaches their 40s. According to the American Society of Plastic Surgeons (ASPS), most of the patients seeking treatment for spider veins are between the ages of 30 and 60.

The exact cause of spider veins is unknown, although heredity is believed to play a strong role. Research has shown that identical twins sometimes will have spider veins in the same areas of the body and to a similar extent, due to inherited weak vein valves.

Pregnancy and hormonal influences also contribute to the development of spider veins. During pregnancy, the volume of blood in the body increases greatly, but the blood flow decreases from the legs to the pelvis causing veins to swell. Hormonal changes during puberty, pregnancy and menopause also appear to contribute to enlarged veins. Internal disease is rarely the cause of spider veins.

Women are more at risk for spider veins than men. In addition to pregnancy and hormonal fluctuations, other factors that may contribute to spider veins include birth control pills and hormone replacement therapies. Tight girdles or hosiery held up with tight elastic bands also can cause spider veins.

Other factors known to contribute to spider veins include:

• Aging. As a person ages, spider veins are more likely to occur.
  
  
• Leg injury. Injuries to the leg can damage the veins, causing spider veins.
  
  
• Sedentary lifestyle. Not exercising weakens muscles and impairs good blood circulation and healthy veins.
  
  
• Long periods of sitting or standing. This can cause blood to pool, enlarging veins.
  
  
• Obesity. Excess weight increases pressure on the veins.
  
  
• Sun exposure. People with light colored skin are susceptible to spider veins on the nose or cheeks that may be caused by sun exposure.

The dilated vessels that make up spider veins may appear as short, unconnected lines or as groups of veins connected in a “sunburst” pattern. They often resemble a spider web or a tree with branches.

In some cases, spider veins may be barely noticeable, while in others, they may cover a large area of skin. Although they can appear on the face, spider veins more often appear on the legs because the pressure on the valves within veins is greater, due to gravity and body weight. Consequently, the veins work harder to overcome these forces.

Spider veins usually are considered medically harmless. Nonetheless, some patients may experience a dull, aching sensation after prolonged standing. In other cases, this discomfort may be more intense and manifest as a throbbing, burning sensation.

A physician will perform a complete physical examination and compile a thorough medical history. The patient will be asked about their symptoms and a list of current medications will be taken. The physician will also ask the patient about general health because people with certain conditions (e.g., circulatory problems, heart conditions, diabetes) may be advised against treatment.

During the physical exam, the physician will closely examine the legs or other areas where the veins are present. Occasionally, x-ray (low doses of electromagnetic radiation to create images on film paper or fluorescent screens) or ultrasound (high-frequency sound waves to create images of internal organs or tissue) may be used to assess vein disorders and the severity of the problem.

There are several options available for treating spider veins, and they are usually effective. The American Academy of Dermatology notes that treatment procedures have an 80 to 90 percent chance of improving the appearance of spider veins.

Support hosiery is often the first level of treatment recommended for patients with spider veins. This gently compresses the leg muscles, which helps veins move blood and keeps them from stretching. However, many patients with spider veins choose sclerotherapy, the chief method for treating both spider and varicose veins.

Sclerotherapy is a procedure that is relatively inexpensive, rarely results in scarring and has few adverse consequences. It is also relatively painless for most patients and requires no anesthesia. During the procedure, the physician uses a very fine needle to inject a dose of concentrated salt solution (saline) or a specially developed chemical solution into the spider vein. This irritates the lining of the vessel, causing it to swell and stick together. After the vein closes up or collapses, it turns into scar tissue that is absorbed by the body over a period of months. Blood that previously had traveled through the spider veins will shift to other nearby blood vessels. 

A dermatologist or a vascular surgeon can perform the procedure, usually on an outpatient basis. The type of physician used depends on the diameter of the blood vessel because treatment of larger vessels is associated with more complications (e.g., blood clots).  

In most cases, between one and three treatments are necessary to successfully treat a spider vein. Each session typically lasts between 15 and 45 minutes. Treatments are often scheduled between four and six weeks apart to allow for proper healing. Sometimes a number of larger veins can be injected during a single treatment session. In addition, any larger varicose veins that may be attached to spider veins will likely be treated at the same time.

Most patients experience few side effects from sclerotherapy. When they do occur, they are usually short-lived. Possible side effects include swelling, bruising, itching, redness, soreness and muscle cramps. Patients may also experience a stinging sensation at the injection sites.

Patients can resume normal activities immediately after a sclerotherapy session. However, they may be advised to avoid strenuous activities for the first 24 hours.

Other treatments that may be used to treat vein conditions such as spider veins include:

• Electrodesiccation. Electrical current is used to seal off veins.
  
  
• Laser surgery. Uses the heat of high-intensity light to selectively destroy abnormal veins.
  
  
• Surgical ligation and stripping. An incision is made in the skin and the damaged vein is either removed or tied off.
  
  
• Ambulatory phlebectomy. Veins are removed through a series of small incisions along the path of an enlarged vein.

In some cases, a physician may use a combination of these techniques to treat spider veins.

Spider veins that appear during pregnancy often disappear on their own without treatment within three months after the baby is delivered. For this reason, pregnant women are often encouraged to postpone treatment for spider veins. Women who are breastfeeding may also be instructed to postpone treatment until they cease nursing. This is due to the fact that physicians are unsure of the effect the solutions used during sclerotherapy will have on a nursing infant.

While treatment for spider veins is usually successful, there are certain side effects and risks associated with the procedure. These include:

• Allergic reaction. Allergic reactions (an exaggerated response of the immune system caused by a substance) to the solution used in sclerotherapy sometimes occur.
  
  
• Blood clots. Treatments sometimes can cause blood clots that may require further treatment.
  
  
• Pigmentation changes. Brownish splotches may appear that can take several months to fade. This is the result of blood moving outside the blood vessel and depositing in the surrounding connective tissue when the vein is injected. Pigmentation changes do not occur with every injection but are more likely when numerous blood vessels are being treated.
  
  
• Scarring. Permanent scarring occasionally will occur as a result of these procedures.
  
  
• Telangiectatic matting. Fine reddish blood vessels (telangiectasia) may appear near the treated area. This can be treated with further injections.

Spider veins cannot always be prevented. However, people can take some steps that may lower the risk of developing spider veins. These include:

• Exercise regularly. This will increase the level of circulation through the veins. All forms are helpful even simple exercise like walking.
  
  
• Avoid long periods of sitting or standing. Moving around at least every 30 minutes encourages blood flow.
  
  
• Do not cross legs while sitting. This restricts the flow of blood through the veins.
  
  
• Avoid wearing high-healed shoes. Low-heeled shoes work the calf muscles instead of the veins.
  
  
• Eat a diet high in fiber. Constipation can contribute to spider veins. Diets high in fiber include fresh fruits and vegetables, and whole grains such as bran.
  
  
• Avoid tight clothing. Clothing that is very tight and constricts the waist, groin or legs can impair blood flow through the veins.
  
  
• Elevate the legs. Elevating legs above the level of the heart can improve vein circulation. This can be done by lying down and resting the legs on two to four pillows. Legs should be elevated two or more times a day for 30 minutes.
  
  
• Maintain a healthy weight. This takes pressure off the veins.
  
  
• Wear support hose. These will steadily squeeze the legs, helping leg muscles and veins to move blood more efficiently.
  
  
• Wear sunscreen. This helps prevent spider veins in the face. 

Preparing questions in advance can help patients to have more meaningful discussions with their physicians regarding their conditions. Patients may wish to ask their doctor the following questions related to spider veins:

1. What may have caused me to develop spider veins?
   
   
2. Are spider veins dangerous to my health?
   
   
3. What are my treatment options?
   
   
4. How many treatment sessions will I need?
   
   
5. What results can I expect after treatment?
   
   
6. Will I have scarring after I undergo treatment for spider veins?
   
   
7. Is it likely I will develop more spider veins after treatment?
   
   
8. Can you treat my varicose veins while you are treating my spider veins, or do I require separate procedures?
   
   
9. My mother has spider veins. Does this mean that I am likely to develop them as well?
   
   
10. How can I prevent spider veins?