PLEASE NOTE. THE NEW 5TH EDITION OF THE BSAVA MANUAL OF ENDOCRINOLOGY IS NOW AVAIABLE HERE.

There are many potential causes of polyuria and polydipsia. Primary disorders of water balance, although uncommon, should always be considered in the differential diagnoses of polyuria and polydipsia. This chapter discusses physiology of water balance, differential diagnosis, diagnostic approach and specific tests to differentiate diabetes insipidus from primary polydipsia.