What are the prevention and treatment methods for varicose veins?

Varicose veins look more frightening than I expected after seeing the photo. It seemed like just an ordinary disease that I didn't think much of, but now I realize it's not such a simple condition.

Varicose veins occur because the blood that should be flowing back to the heart takes a wrong path.

Are there any preventive measures to avoid getting sick? Maybe related to food or something?

How should we proceed with treatment? I thought surgery was the only option, but after reading other people's posts, it seems there are other methods as well. Varicose veins seem to be a modern ailment.