Varicose veins may not cause any pain. Signs you may have varicose veins include:

• Veins that are dark purple or blue in color
• Veins that appear twisted and bulging; they are often like cords on your legs

When painful signs and symptoms occur, they may include:

• An achy or heavy feeling in your legs
• Burning, throbbing, muscle cramping and swelling in your lower legs
• Worsened pain after sitting or standing for a long time
• Itching around one or more of your veins
• Skin discoloration around a varicose vein

Spider veins are similar to varicose veins, but they're smaller. Spider veins are found closer to the skin's surface and are often red or blue.

Spider veins occur on the legs, but can also be found on the face. They vary in size and often look like a spider's web.

Weak or damaged valves can lead to varicose veins. Arteries carry blood from your heart to the rest of your tissues, and 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. If these valves are weak or damaged, blood can flow backward and pool in the vein, causing the veins to stretch or twist.

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. Hormone treatments, such as birth control pills, may increase your risk of varicose veins.
• Pregnancy. During pregnancy, the volume of blood in your body increases. This change supports the growing fetus, but also can produce an unfortunate side effect — enlarged veins in your legs. Hormonal changes during pregnancy may also play a role.
• 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.

Complications of varicose veins, although rare, can include:

• Ulcers. Painful ulcers may form on the skin near varicose veins, particularly near the ankles. A discolored spot on the skin usually begins before an ulcer forms. See your doctor immediately if you suspect you've developed an ulcer.
• Blood clots. Occasionally, veins deep within the legs become enlarged. In such cases, the affected leg may become painful and swell. Any persistent leg pain or swelling warrants medical attention because it may indicate a blood clot — a condition known medically as thrombophlebitis.
• Bleeding. Occasionally, veins very close to the skin may burst. This usually causes only minor bleeding. But any bleeding requires medical attention.