Impediment comes from a Latin verb that meant "to interfere with" or "to get in the way of progress", as if by tripping up the feet of someone walking. In English, impediment still suggests an obstruction or obstacle along a path; for example, a lack of adequate roads and bridges would be called an impediment to economic development. Impediments usually get in the way of something we want. So we may speak of an impediment to communication, marriage, or progress--but something that slows the progress of aging, disease, or decay is rarely called an impediment.