Final answer:
Varicose veins are swollen, distended, and knotted veins that occur most commonly in the legs when the valves in the veins become ineffective, allowing blood to flow backward and pool in the veins. Factors such as age, gender, family history, and lifestyle habits can increase the risk of developing varicose veins.
Step-by-step explanation:
Varicose veins are swollen, distended, and knotted veins that occur most commonly in the legs. They occur when the valves in the veins become ineffective, allowing blood to flow backward and pool in the veins, resulting in their enlargement and distortion. This is most prominent in the legs due to the pull of gravity, which causes blood to accumulate in the lower limbs. Factors such as age, gender, family history, obesity, pregnancy, standing for long periods, chronic constipation, and long-term alcohol consumption can increase the risk of developing varicose veins. While they are usually not serious and only a cosmetic issue in many people, in severe cases, they can cause pain and other problems.