The International OCD Foundation has published a concise and helpful information sheet about hoarding which you can see here. They also have a handout showing photographs of the various stages of clutter.
As you can see, it’s not an all or nothing thing. Everyone has some amount of clutter and that’s perfectly normal.
Is the Clutter Causing a Problem for You or Your Safety?
If an ambulance had to come into your house with a stretcher, could they get to every room in your house?
Can you cook and use your kitchen and bathrooms as intended?
Is Clutter Getting in the Way of Living Your Life?
Are you concerned about the amount of time you spend processing your stuff?
Do you feel like you spend a lot of time trying to manage your clutter but never really making progress?
Will Clutter Make Life Difficult for Future You?
Although there are extreme situations where the entire contents of your house have to be removed, for the most part people usually aren’t at quite that level. Sure they have trouble finding things, especially paperwork, and often choose to eat out rather than face the clutter in the kitchen, but things aren’t THAT bad!
The trick is to catch them before they get that way. I work with many clients who tell me the one thing they wish they would have done is start ten years ago, when they were fitter and more mobile, when they had more physical energy and mental stamina to deal with the thousands (if not more) of decisions that come along with clearing clutter.