Haematuria

This elephant has haematuria. They also have polyuria, assuming that's defined as more than 3 litres in 24 hours in elephants as it in in humans. I assume it is.

Definition

Blood in urine.

• Frank haematuria - urine that is visibly red/brown. This is always urgent.
• Microscopic haematuria - urine that isn't visibly red, but on analysis/dipstick shows a small content of blood.

Epidemiology

Relatively common, especially in older people. Its a good predictor for serious disease - in one study of 50+ men, pathological conditions were found in 31 out of 44 who had haematuria at least once.

Pathophysiology

Its almost always a problem in the urinary tract. Blood is a massive molecule, so no matter how nackered the kidneys are, they won't let blood through. So the blood comes through somewhere between the kidney and the urethra.

One common confounding factor is menstrual blood. Often a woman in the middle of a period will get blood in their urine, from the vagina. This is not haematuria.

Clinical and Associated Features

Commonly, alongside blood in the urine, they can get abdominal pain and dysuria (pain or difficulty urinating).

In some of the causes, such as urinary tract infection, you will get fever. In others like urological cancer, you will get weight loss.

Differential Diagnosis

Simple version: TITS - Trauma Infection Tumour Stones.

• Renal calculi - stones cause loin pain, and damage the ureters, causing blood.
• Urinary tract infection - commonly present with fever, general malaise and in the older generation, commonly delirium.
• Urinary tract malignancy - Not massively common, but serious.
• Glomerulonephritis - also accompanied with kidney pain, and with lack of urinating. Often systemically unwell too.
• Bleeding disorders - anticoagulants can also cause it.
• Rhabdomyolysis - this is pretty rare, but on someone with recent physical trauma, clots or immobility, pink urine should be an alarm bell!
• Acute intermittent porphyria - also pretty rare, but if you leave their wee to stand, it goes brown/red, sometimes being mistaken for haematuria.

Investigations

Kick off with Urinalysis. This is mandatory to confirm there is actually blood in the urine.

• As with most things, do a FBC and U+Es.
• Clotting studies can rule out bleeding disorders.
• Urine culture is helpful too.