Dear doctor...

What did medieval physicians prescribe for stomach ache? And could weasels' testicles really help you conceive?

- James Freeman

James Freeman delves into the sources to find eight curious cures from the Middle Ages

...my urine has turned black!

What does your wee say about your health? Well, plenty – but perhaps not in quite the way medieval physicians understood it. Before the in-depth study of anatomy and physiology, establishing the causes of symptoms relied on theories that today seem primitive or foolish. However, they were often based on long-established ideas about the body and its function.

Medieval treatises on uroscopy – the study of urine – identified up to 20 colours, each indicating certain diseases. Many texts on this subject were accompanied by drawings of glass flasks filled with liquid coloured with an appropriate pigment. These might be arranged in a circular shape with descriptive labels (as shown far left), helping readers to memorise the key diagnostic details. Perhaps unsurprisingly, black was the worst possible colour, and was generally agreed to indicate imminent death.

Because of prohibitions against opening the body (which extended to postmortem dissections), medieval doctors were reliant on external indicators. This included variations in a patient's pulse but also the colour, texture, layers, smell and even taste of their urine.

The doctor's role was to understand a patient's nature: specifically, the four fluids or ‘humours’ inside the human body.

In the treatise De Natura Hominis (‘On the Nature of Man’), by the ancient Greek physician Hippocrates (c460-c375 BC) or his pupil Polybus, it was determined that there were four such humours: blood, phlegm, black bile and yellow bile. Disease was caused by imbalances in these humours, or when they became ‘corrupted’ or concentrated in a part of the body.