As rid mentioned, it is of great importance go go back to where it all starts: The cell. Ensure that you are up to date with your anatomy and physiology, as the pathophys texts will always refer to these two sections. Pathophys is the study of disease/disorder, i.e. what goes wrong, and you cannot study what goes wrong if you don't know what is right (Anat & Phys).
It is a big section, but very important. Should you know the cause of the patient diagnosis (Pathophys behind the diagnosis), it will be easier to treat and your treatment will then be based on educational decision making, rather just the protocol.
Good luck!!