Ron answered a question about the definition of severe ME
He said there are no official definition but from his point of view, a severe patient is a bedbound patient and unable to go out to see a doctor. In my opinion it would fall in the category of 'very severe'.
I thought about the issue a few days ago while answering Dr Jason's questionnaire, what is the definition of bedbound and housebound? In my opinion there are many shades of bedbound and housebound of ME patients. It is used to stratifying severity but it has pittfalls. Some say they are bedbound but can use their tablet, their phone and talk, while others need a dark room and no noise, no music, and can't talk. Some manage to go to the washroom while others can't.
The spectrum of housebound is quite wide too, from being able to a few steps around the house, to be able to prepare meals and do light housekeeping but not getting outside of their home, while others manage out for dr visits. Then there are those who are managing out with the help of assistive devices or caregivers but for a limited time, and have simply traded the little energy they have and skip showering, for instance who by strict definition would not qualify for the housebound definition but still would be considered very sick.
There are many, many shades of housebound / bedbound and within these categories, many shades of severity.