Basically, you are being given disability for what you stated, your "limitations" and that is what is focused on. They look at what you can and cannot do.
They don't put a label on your illness. I would suggest, unless there is some pressing need to know what your exact disability is based on, let sleeping dogs lie and be glad you got disability. I am not being disrespectful or taking your query lightly. I understand what you are saying. I have never heard of someone being told the reason they have been awarded disability benefits...they applied, told the govt what their health issues were and were or were not given benefits.

Please don't worry about reviews. I was awarded disability benefits 20 yrs ago, was also told I would be reviewed every few yrs and have only been reviewed once. It was simply a letter they asked me and my docs to fill out.

take care, D.