Haematuria is a common presenting feature of diseases of the kidney or the renal tract. It is also common in screening tests, single dipstick tests being positive in perhaps 5% of individuals. Age and whether the blood is visible (macroscopic) or non-visible (microscopic) impact largely on whether the explanation is likely to be broadly urological or nephrological. Origins are most commonly simple or urological.
Macroscopic bleeding is rare in renal disease, and urine colour is then usually more rather smoky than red except when there is very acute inflammation. The chief urological causes are neoplasia, infection, stones, and trauma. Some traditionally medical conditions may cause simple bleeding; examples include cystic kidney diseases, papillary necrosis and macro- or microvascular ischaemic lesions.
The major concern to nephrologists is that even non-visible haematuria may be a pointer to inflammatory or destructive glomerular processes. The presence of casts or dysmorphic red cells is a pointer to glomerular disease; more important in clinical practice are the three other key markers of renal disease: proteinuria, renal impairment in the absence of urinary tract obstruction, and hypertension.
In the general population, microscopic haematuria does associate with a long-term increased risk of end-stage renal failure, so after negative investigations, occasional long-term checks are indicated. The case for population screening for haematuria appears weak.
Cystic Kidney Diseases From the Adult Nephrologist’s Point of View
