Varicose Veins -

Varicose veins are enlarged, swollen, and twisting veins, often appearing blue or dark purple. They happen when faulty valves in the veins allow blood to flow in the wrong direction or to pool.

Symptoms -

When suddenly standing up, some individuals experience leg cramps
Aching legs
Legs feel heavy, especially after exercise or at night
A minor injury to the affected area may result in longer bleeding than normal
Swollen ankles

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.

Risk factors -

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.

Complications -

Complications of varicose veins, although rare, can include:
Ulcers. Extremely painful ulcers may form on the skin near varicose veins, particularly near the ankles. Ulcers are caused by long-term fluid buildup in these tissues, caused by increased pressure of blood within affected veins.
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 swell considerably. Any sudden leg swelling warrants urgent 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 warrants medical attention because there's a high risk it can happen again.

Exercising -

Watching your weight
Eating a high-fiber, low-salt diet
Avoiding high heels and tight hosiery
Elevating your legs
Changing your sitting or standing position regularly