Adults and Bedwetting, Wetting the bed at night is surprisingly common, although very few people talk about it. It affects about one person in throughout adult life. However, when adults wet the bed it is often an indication of an underlying illness, disease, or a symptom of other untreated medical conditions. For adults, wetting the bed can not only be a devastatingly embarrassing condition, but it is often a sign of other medical troubles. Find out what may be causing you to wet the bed when you're an adult and what you can do to treat it.