What causes varicose veins?
D005260:Female; D006801:Humans; D008855:Microscopy, Electron, Scanning; D008875:Middle Aged; D009765:Obesity / Q000150:complications; D011247:Pregnancy; D011249:Pregnancy Complications, Cardiovascular / Q000209:etiology; D014648:Varicose Veins / Q000209:etiology*; D014680:Veins / Q000648:ultrastructure