This text aids medical students and trainee doctors in developing their knowledge of the conditions covered and improving their ability to clinically assess patients and formulate a management plan. Once doctors are comfortable in interpreting these graphs, they can use them in consultations with patients about their kidney condition and so support self-management by patients, an increasingly important aspect of healthcare. Kidney diseases and the speciality of nephrology have traditionally been regarded as difficult to understand. This is compounded by the use of complex definitions and terminology. These complex definitions result from a need to categorise kidney diseases according to the way kidney function changes over time, and then to express this in numbers and words. Central to the assessment of patients is the measurement of kidney function. In our teaching of medical students and trainee doctors, as well as in our clinical practice and interaction with GPs and consultant colleagues, we have found that viewing graphs of patients’ kidney function (estimated glomerular filtration rate, or eGFR) against time is a much easier way of understanding kidney diseases. It provides the patient’s ‘kidney history’ and leads into a description of the natural history and management of their condition. We were surprised to find that this graphical approach is not used routinely in teaching or in daily clinical practice. We therefore believe there is a need for a book that uses this approach and we thus sought to compile a collection of illustrative case studies covering an array of disease categories, together with patients’ eGFR readings.