It is the responsibility of all practitioners to be able to recognise what they are not qualified to treat and to have the confidence to refer to other health professionals. "Differential Diagnosis for Primary Practice" aids practitioners in the differential diagnosis of signs and symptoms and in recognising the clinical indications for patient referral. It is intended for use chiefly by non-medically qualified practitioners, particularly those working in the field of manual therapy. Its aim is to help practitioners to arrive quickly and logically at the correct diagnosis and in doing so to become aware of anything which does not fit the diagnosis and so needs to be referred.