Along with indulgently early bedtimes and some very on-trend graying hair, varicose veins are one of the wonderful things we can look forward to as we grow older. But an especially fortunate few of us may develop them earlier on. Why, you ask? Well, according to this new SciShow video, gravity deserves a lot of the blame. Why do we get varicose veins at all? Well, remember that while your arteries are responsible for carrying oxygen-rich blood away from your lungs and heart, your veins have the equally important job of carrying blood loaded with carbon dioxide back up there for recycling. Veins are doing this all over your body, but that job gets a little bit harder when they're fighting against gravity (i.e. in the lower half of your body, especially your legs and feet). So blood tends to pool there, which causes your veins to become enlarged and a bit lumpy. As the video explains, anyone with veins can develop varicose veins. But there are a few factors that can make them more likely: Getting older, becoming pregnant, gaining weight, not staying active, and your genetics can all play a role. That means that, for some of us, varicose veins are just inevitable. But you can do your best to prevent them by exercising regularly and not sitting for too many hours at a time. Luckily, varicose veins are not necessarily a health concern. In some cases, they can be painful or make it more likely for blood clots to form. And in those scenarios, your doctor may suggest some self-care strategies (e.g. wearing compression stockings) or more intense treatments (e.g. sclerotherapy, which closes up the veins). But most of us can stand to have a few varicose veins without any worries. And as long as they're not causing problems, there's no reason to hate 'em.