IgA nephropathy is the most common form of inflammatory kidney disease causing uraemia world-wide and initially often a silent disease with microscopic haematuria as the only clinical finding. If left untreated, progress to terminal uraemia and dialysis is not uncommon as at least 30 % develop end stage renal failure. Awareness of the existence of the disease among GPs, internists and urologists may be helpful, not disregarding microscopic haematuria, particularly in combination with albuminuria or finding of renal casts in the urine, especially in younger individuals. No diagnostic marker in blood or urine for the disease has yet been established so kidney biopsy is still needed to confirm diagnosis. The degree of renal dysfunction, hypertension, albuminuria, and histology findings at time of diagnosis have significant impact on renal outcome. Potential biomarkers for progressive disease have been described but no one has so far been implicated in clinical practice. Until now, the only evidence-based medication consists of blockers of the renin-angiotensin-system and corticosteroids. However, new and potentially more specific drugs are under clinical investigation. Early intervention is mandatory to prevent disease progression. Thus, we want to alarm other specialists to an increased alertness for this disease, referring patients at an early stage of possible IgA nephropathy to the nephrologist for diagnosis and interventions.