Further to my article on reading urine colour, I felt like I should explore the important clinical sign of haematuria (blood in the urine) in more detail. This can be frightening for a patient to experience, and clinically important to detect early.

Haematuria may be macroscopic (visible to the naked eye), or microscopic (invisible to the eye but detectable on a test). Doctors divide causes anatomically, into pre-renal, renal, and post-renal (before, at, and after the kidneys). Let's explore these visually: