Arteries carry blood from your heart to the rest of your tissues. Veins return blood from the rest of your body to your heart, so the blood can be recirculated. To return blood to your heart, the veins in your legs must work against gravity.
Muscle contractions in your lower legs act as pumps, and elastic vein walls help blood return to your heart. Tiny valves in your veins open as blood flows toward your heart then close to stop blood from flowing backward.
What are the causes of varicose veins? In some instances, the absence or weakness of valves in the veins may cause poor venous circulation (blood flow in the veins) and lead to varicose veins. Valves inside veins normally act to ensure that blood in the veins does not flow in a backward direction (retrograde) away from the large (deep) veins and the heart
Causes of varicose veins can include:
- Age. As you get older, your veins can lose elasticity, causing them to stretch. The valves in your veins may become weak, allowing blood that should be moving toward your heart to flow backward.
Blood pools in your veins, and your veins enlarge and become varicose. The veins appear blue because they contain deoxygenated blood, which is in the process of being recirculated through the lungs.
- Pregnancy. Some pregnant women develop varicose veins. Pregnancy increases the volume of blood in your body, but decreases the flow of blood from your legs to your pelvis. This circulatory change is designed to support the growing fetus, but it can produce an unfortunate side effect — enlarged veins in your legs.
- Varicose veins may surface for the first time or may worsen during late pregnancy, when your uterus exerts greater pressure on the veins in your legs. Changes in your hormones during pregnancy also may play a role. Varicose veins that develop during pregnancy generally improve without medical treatment three to 12 months after delivery.
Risk factors – varicose veins
These factors increase your risk of developing varicose veins:
- Age. The risk of varicose veins increases with age. Aging causes wear and tear on the valves in your veins that help regulate blood flow. Eventually, that wear causes the valves to allow some blood to flow back into your veins where it collects instead of flowing up to your heart.
- Sex. Women are more likely to develop the condition. Hormonal changes during pregnancy, premenstruation or menopause may be a factor because female hormones tend to relax vein walls. Taking hormone replacement therapy or birth control pills may increase your risk of varicose veins.
- Family history. If other family members had varicose veins, there’s a greater chance you will too.
- Obesity. Being overweight puts added pressure on your veins.
- Standing or sitting for long periods of time. Your blood doesn’t flow as well if you’re in the same position for long periods.
The causes of varicose veins may be primary, secondary, or congenital. Primary varicose veins develop as a result of an inherent weakness in the wall of the vein. Varicose veins can have a hereditary factor and often occur in several members of the same family. Varicose veins that develop after trauma or deep vein thrombosis are of secondary cause. Congenital varicose veins are due to disorders in the natural development of the venous system, and usually are part of a vascular mal – formation in the limb, present at birth. In addition to varicose veins, these individuals may also have an enlarged and longer limb and often have birthmarks (port-wine stains), like in Klippel Trenaunay Syndrome (KT syndrome). No matter the cause, defective venous valves may cause venous blood to stagnate in the leg, leading to increased pressure in the veins.
This may result in further enlargement of the varicose veins, increasing the likelihood of symptoms, and causing complica – tions such as skin changes and ulcer formation. Blockage of the pelvic veins may severely aggravate the effects of varicose veins, requiring a separate treatment.
What Are Spider Veins?
Spider veins (also called telangiectasias) are clusters of tiny blood vessels that develop close to the surface of the skin. They are often red, blue, or purple; and they have the appearance of a spiderweb. They are commonly found on the face and legs.
What is the cause of spider veins?
In women, symptoms may be worse during certain parts of the menstrual cycle or during pregnancy. Less common is swelling, ulcers and a darkening of the skin, especially in the ankle region. Occasionally, varicose veins can form a painful blood clot with inflammation of the vein, a condition called thrombophlebitis.