Consulted various web sites for this.

 

There are a couple of diffent types.

 

Selective Amnesia: this is when a person remembers parts of events that happened in a certain time frame (i.e. they can only remember when they were in groups of three with the abusive father).

Generalised Amnesia: this is when the person can't remember anything from their entire life.

Continuous Amnesia: this is when a person can't remember events that begin at a certain point in their life onwards (i.e. they can't remember what happened from when they were seven to their current age).

Systematised Amnesia: this is most likely what Tsunade thinks Naruto has. It's characterized by loss of memory around a certain subjec (i.e. when a person represses every memory that includes their uncle).