“Hoarders” is an often painful look inside a disease that can bury its sufferer — literally at times — in its symptoms. Each hourlong episode profiles two people on the verge of a personal crisis, all caused by the fact that they are unable to part with even the tiniest possessions, and the cumulative effect becomes a mountain of junk and garbage overtaking their home or apartment. If they don’t respond to professional help, the consequences sometimes involve eviction, kids being taken away, or even jail time.