There is some variability in the length and approach of the training of doctors which is undertaken by different UK Medical Schools. The 'Classical' approach - still the commonest - is a five year course, broken into two distinct segments:
Two years of theory: Anatomy, Physiology, Biochemistry, Pharmacology, Pathology, Genetics, Sociology, Psychology, Bacteriology, Embryology.
One year of half-and-half theory (more Pathology) and early clinical experience, followed by one year of full time hospital-based experience, shadowing 'real' doctors, followed by the final year which is basically one long revision course.
....but the lack of early clinical experience, and the predominance of over-technical theory in the Pre-clinical phase has come under criticism. Some Medical Schools have adopted what they believe to be a more integrated course structure. Such integrated courses, for example, may expose students to direct dialogue with patients within their first week at medical school - even though their knowledge at that point of the patient's disease state or their treatment is close to zero.