Private debt is not considered as a macroeconomic concept because the personal debt is an amount that is bought by an individual or private business which can be in the form of personal loans, business loan, credit card and many more.

Suppose an individual who wants to purchase a house goes to bank for a personal loan, that will not be taken as macroeconomic concept because the individual borrows the loan for their own self interest.

When the national debt or public debt is considered that is, if the government borrows from the bank will be considered as a macroeconomic economic concept because this loan is related with the development of the economy as a whole.