Anosmia is the medical term used to describe a loss of smell or diminished sense of smell. The cause can be due to a nasal obstruction, such as a polyp, or a disorder of the neural pathways that send odor messages to the brain. According to Drugs.com, recent studies indicate anosmia may be one of the first symptoms of Alzheimer's disease. Symptoms of the condition are generally minor, although some people have severe cases.
Diminished Smell
The primary effect of anosmia may not be noticed right away if the individual gradually loses the ability to smell odors. This can be due to the cause, such as a polyp that is slowly growing, or some other obstruction of the nasal passages. Subtle scents may not be recognized, and an individual may not even realize this has happened. Pungent scents, like smoke or soured food, that aren't perceived by the nose are more obvious effects of anosmia.
Diminished Taste
An effect of a reduced sense of smell is a diminished sense of taste. Some individuals can't taste foods at all, says MayoClinic.com. MedlinePlus explains that some individuals can still distinguish salty, sweet, sour or bitter tastes because these are first identified by taste buds on the tongue. Other sensations from spices like cayenne pepper can be felt in the nerves of the face despite the individual's inability to recognize the smell.
Complications
Changes in a person's ability to smell can lead to complications that can be serious. MayoClinic.com says anosmia can contribute to changes in eating habits, such as reduced interest in food or appetite. Moderate cases can cause an individual to lose weight, experience malnutrition or become depressed.
