[Nephrological diagnostics with the general practitioner's toolbox]

Nephrological diagnostics with the general practitioner's toolbox Abstract. Kidney diseases are often asymptomatic or present nonspecifically and are frequently diagnosed by chance as part of a laboratory check up. In newly diagnosed renal failure, the physician should determine the dynamics (acute versus chronic) and identify the cause of the renal dysfunction based on history and additional tests. This is crucial to identify treatable kidney diseases and to provide patients with the adequate therapy. The identification of the underlying disease and determination of its severity are necessary to estimate the renal and cardiovascular prognosis. Finally, the degree of renal insufficiency is important for dose adjustment of renally eliminated drugs and assessment of possible complications of renal failure. Most general practitioners have the necessary diagnostic tools at their disposal to carry out the above assessments and decide when a specialist nephrological referral is advisable. To diagnose and stage renal failure, serum creatinine must be measured and the glomerular filtration rate (GFR) estimated. The second pillar is the examination of urine (proteinuria, albuminuria, urine sediment). Depending on the findings, further laboratory tests may be useful. Renal ultrasound is the primary imaging method in patients with acute and chronic renal failure. In this article, the above mentioned methods are described in more detail and their potential pitfalls are discussed.