Haematuria
The presence of blood in the urine is termed haematuria. Haematuria has many causes ranging from the insignificant to life-threatening cancers and is often a result of urinary tract infection (UTI). The patient should therefore be asked whether the blood was accompanied by symptoms of urinary tract inflammation such as dysuria, pain, urinary frequency or whether the urine smelled offensive. In all patients with a history of haematuria, the urine should be examined by dipstick and cultured if this suggests infection (see later). The extent of investigation required for a confirmed infection is guided by patient characteristics; however, all patients with symptomatic infections should be treated with appropriate antibiotics and the urine retested for blood once the infection has resolved. It is important to remember that UTI itself can be the first sign of serious urinary tract pathology. Uncommonly, urine discolouration that is reported as haematuria may be caused by myoglobinuria, beetroot intake and drugs such as rifampicin. It is generally advisable to investigate for haematuria anyway. Haematuria may be visible or non-visible and associated with other LUTS or asymptomatic, and this is the starting point for subsequent enquiry.
Visible haematuria
Visible haematuria is arguably the most important symptom in urology as it implies urological cancer until proven otherwise, and all patients including those with demonstrated infection should undergo investigation. The patient may notice the blood at the beginning, throughout or at the end of the urinary stream, and this sign may give an indication of its origin and cause. Initial haematuria often originates from the prostate or urethra and as such is less likely to reflect bladder or upper urinary tract pathology, whereas haematuria throughout the stream implies the blood emanates from the bladder or above. Terminal haematuria may indicate upper tract bleeding. This differentiation is unreliable, however, and all patients require the same investigation with upper urinary tract cross-sectional imaging by computerised tomography including a urographic phase and cystoscopy as a minimum.
Non-visible haematuria
Non-visible or microscopic haematuria is defined by the presence of more than three erythrocytes per high-power field on microscopy or at least 1+ on dipstick of a fresh midstream urine sample. It is usually detected in the community on routine urine testing or during the investigation of symptoms. A few erythrocytes in the urine are common and often found after heavy exercise. After exclusion of infection as a cause, a single episode of non-visible haematuria accompanied by LUTS or persistent asymptomatic haematuria is clinically significant and should be investigated.
Asymptomatic non-visible haematuria commonly represents early chronic kidney disease, and patients under the age of 40 with no other risk factors for urothelial malignancy should be investigated with urine protein/creatinine ratio and first referred for nephrological rather than urological opinion if evidence of deteriorating glomerular filtration rate, significant proteinuria or hypertension is present. The patient should be asked if there has been a recent upper respiratory tract infe...