Anosmia is the inability to perceive odor or the loss of the sense of smell. Anosmia can be temporary, but some forms, such as from an accident, can be permanent. Anosmia is due to a number of factors, including inflammation of the nasal mucosa, obstruction of the nasal passages, or destruction of a temporal lobe. The inflammation is due to chronic mucosal changes in the lining of the paranasal sinus and the middle and superior turbinates.

When anosmia is caused by inflammatory changes in the nasal passages, it is treated simply by reducing the inflammation. It can be caused by chronic meningitis and neurosyphilis that would increase intracranial pressure for a long period of time.

Many patients may experience unilateral anosmia, often as a result of minor head trauma. This type of anosmia is normally only detected if the two nostrils are tested separately. Using this method of testing each nostril separately will often show a reduced or even completely absent sense of smell in either or both nostrils, something that is often not revealed if both nostrils are tested simultaneously.

Anosmia can have a number of deleterious effects. Patients with sudden-onset anosmia may find food less palatable, although congenital anosmatics rarely complain of this, and none report weight loss.

Loss of smell can lead to loss of libido, although this does not generally apply to congenital anosmics.

To diagnose anosmia, the doctor will investigate any injuries related to anosmia, which could include upper respiratory infections or head injuries. Psychophysical assessment of order and taste identification can be used to identify anosmia. An exam of the nervous system is done to see if the cranial nerves are damaged.

Although anosmia caused by brain damage cannot be treated, anosmia caused by inflammatory changes in the mucosa can be treated with glucocorticoids. may have to be repeated after a short time. Along with medication, the pressure in the upper area of ​​the nose should be relieved by aeration and drainage. Anosmia caused by a nasal polyp can be treated with steroid treatment or removal of the polyp.

Loss of smell can also be dangerous because it makes it hard to detect gas leaks, fires, and spoiled food. The common view of anosmia as trivial can make it more difficult for a patient to receive the same type of medical help as someone who has lost other senses, such as hearing or sight.