[Sense of smell].

About two million Americans suffer from anosmia. Most result from nasal obstruction, head injuries, and viral infections. Brain disorders like epileptic seizures, tumours, and dementia can distort can distort the sense of smell. Anosmia adversely affects patient well-being. Patients cannot detect spoiled food, gas leakage, or dangerous smoke. They are unable to distinguish flavour and smell the springtime or the ocean. Many products as soaps, cat litter, toilet paper, etc. are perfumed because consumers will more readily buy a product that smells nice than one that has no smell at all. Historically, the importance of odors was very different. The ancient Romans loved exotic aromas during their banquets and orgies. In the Middle Ages the church did not like fragrances. The French revolution of 1789 brought a revolution of deodorization to Europe. Today, fragrance companies' increasing sales are an indication of the power of odor.