Is there a Relationship between Odors and Disease?
“The smell of disease”
Although the smell is the most unknown of the senses, it is well known that smells can provoke emotional, physical, and mental reactions. Thus, some unpleasant and penetrating smells, called odors, have historically been associated with both death and the transmission of disease.
In the past, doctors smelled patients’ breath, urine, and even feces to determine whether they were sick or not. Some diseases are said to be distinguishable by their characteristic smell: diabetes from rotten apples, yellow fever from butchers, typhus from baked bread, and liver failure from raw fish.
We, humans, sweat to regulate our temperature. Through exudation, we release products of metabolism into the air that have a characteristic smell, so that when we are sick, microbes in the gut or on the skin may break down the metabolized substances into more odorous ones.
Before medical research began to be perfected in the 18th century, analysis of the odour and colour of urine was the most widely used diagnostic tool. Since the Middle Ages, there were urine wheels, divided into 20 possible colors, with olfactory categories that marked analogies between these characters and the disease. Patients carried their urine in transparent glass jars and doctors, besides…
