Causes of Spider Veins
The cause of spider veins is blood backing up in the veins. When the one-way valves in the veins weaken, blood can leak back into the vein and collect there. In addition, there are certain factors that increase a person's risk of developing them. Some of these risk factors include standing for long periods of time, pregnancy, exposure to the sun, obesity, and having a family history of vein problems.
Spider veins are similar to varicose veins, but they are smaller and closer to the surface of the skin. They can cover either a very small or very large area of skin. They are often blue or red, and they can look like tree branches or spider webs with their short, jagged lines. Spider veins are caused by blood backing up in the veins.
The heart pumps blood filled with oxygen and nutrients to the entire body. Arteries carry blood from the heart toward the other parts of the body. Veins carry oxygen-poor blood from the body back to the heart.
The squeezing of leg muscles pumps blood back to the heart from the lower body. Veins have valves that act as one-way flaps. These valves prevent the blood from flowing backwards as it moves up the legs. If the one-way valves become weak, blood can leak back into the vein and collect there. This problem is known as venous insufficiency.
Risk factors are things or conditions that increase the risk of developing a health condition. While not causes of spider veins, there are certain factors that increase a person's chances of developing them. These risk factors for spider veins include:
- Increasing age.
- Having family members with vein problems (or being born with weak vein valves).
- Hormonal changes. These occur during puberty, pregnancy, and menopause. Taking birth control pills and other medicines containing estrogen and progesterone also increases the risk of varicose or spider veins.
- Pregnancy. During pregnancy, there is a huge increase in the amount of blood in the body, which can cause veins to enlarge. The expanding uterus also puts pressure on the veins. Spider veins usually improve within 3 months after delivery. A growing number of abnormal veins usually appear with each additional pregnancy.
- Obesity, leg injury, prolonged standing, and other things that weaken vein valves.
- Sun exposure, which can cause spider veins on the cheeks or nose of a fair-skinned person.