To hear audio pronunciation of this topic, purchase a subscription or log in.

That quality of a substance that renders it perceptible to the sense of smell.
Odors have been classed as (1) pure, (2) those mixed with sensations from the mucous membrane, and (3) those mixed with the sensation of taste. Although classification attempts are useful, it is important to realize that most complex substances do not produce a single odor.

In the past, body and breath odors were sometimes relied on to suggest diagnoses; this is rarely done in contemporary health care. Examples are a “mousy” odor present in the breath of patients with liver failure (liver breath); an odor of stale urine (uremic breath) in uremia; and the sweet smell of acetone in diabetic ketoacidosis. The characteristic smell of some alcoholic beverages can be detected in the breath. In some hospitals, the employees and staff who work in the presence of patients are asked to refrain from wearing scented substances such as perfumes, hair sprays, underarm deodorants, or after-shave lotions. This is done to prevent olfactory discomfort to patients. Individuals who have just returned from surgery or who have asthma or other respiratory problems are particularly sensitive to odors. Electronic devices for detecting and characterizing odors have been developed.

SEE: breath; SEE: odorimetry; SEE: pheromone

There's more to see -- the rest of this topic is available only to subscribers.