Your regular cotton socks may be doing more harm than good when it comes to your health. The blood in your veins has to work against gravity to flow back to the heart. Anything that impedes that flow—such as circulation problems, lack of movement (especially after an injury or surgery), or weakness in the walls of the veins of the legs (aka: venous insufficiency) — can result in blood pooling in the veins of the lower legs or feet, leading to leg swelling, achiness, fatigue, varicose veins and pain; it could also predispose you to a venous clot.
Compression socks were initially designed to help improve blood-flow in post-surgical patients, diabetics, people with circulatory issues, varicose veins, swelling and pain. These people were usually bed-ridden and completely inactive, so they needed a tight fitting sock to help blood circulate and return to the heart, preventing pooling, blood clots and swelling in their lower extremities. However, most medical compression socks are painful to wear because they are so unbelievably tight and can even cut off circulation, which leads to a whole other host of issues.