Haematuria simply means the presence of red blood cells in the urine. The Renal Association and the British Association of Urological Surgeons have recently recommended that haematuria is classified as visible (previously macroscopic) or non visible (previously microscopic). Non visible haematuria may be spurious, transient or persistent and also symptomatic (urgency, frequency, dysuria) or asymptomatic. Causes are usually urological but may also be renal – the figure shows a red cell cast in a patient with glomerular (renal) haematuria (Fig. 4.1).

The commonest cause of spurious haematuria is contamination of the urine specimen by menstrual blood loss. The term is also used to describe false positive dipstick tests which occur in rhabdomyolysis and haemoglobinuria because myoglobin and haemoglobin cross react with the chemical reagent on the test strip; and the red or pink urine that is sometimes seen with foods such as beetroot or drugs such as rifampicin.

The two most important ones are urinary tract infection and vigorous exercise. Patients with suspected uncomplicated urinary infection should receive an appropriate empirical course of antibiotic e.g. trimethroprim followed by repeat urine dipstick 2 weeks later. If the follow up dipstick is negative no further tests are required. See below for what to do if the dipstick is positive

The likelihood of finding a urological malignancy in a patient with haematuria depends on age, gender and whether the haematuria is visible or non visible, as shown in the box below.