Impaired smell is the partial or total loss of the sense of smell.

Loss of smell; Anosmia

The loss of smell can occur as a result of nasal congestion or blockage of the nose and isn't serious, but it can sometimes be a sign of a nervous system (neurological) condition.

Temporary loss of the sense of smell is common with colds and nasal allergies, such as hay fever (allergic rhinitis). It may occur after a viral illness.

Some loss of smell occurs with aging. In most cases, there is no obvious or immediate cause, and there is no treatment.

The sense of smell is often lost with disorders that prevent air from reaching the part of the nose where smell receptors are located (the cribriform plate, located high in the nose). These disorders may include nasal polyps, nasal septal deformities, and nasal tumors.

Other disorders that may cause a loss of the sense of smell include:

• Alzheimer's dementia
• Disorders of the endocrine system
• Head trauma
• Nervous disorders
• Nutritional disorders
• Tumors of the head or brain

Many medications may change or decrease the ability to detect odors.

The sense of smell also enhances your ability to taste. Many people who lose their sense of smell also complain of a loss of the sense of taste. Most can still tell between salty, sweet, sour, and bitter tastes, which are sensed on the tongue. They may not be able to tell between other flavors. Some spices (such as pepper) may affect the nerves of the face and may be felt rather than smelled.

• Use of certain medications (such as amphetamines, estrogen, naphazoline, phenothiazines, prolonged use of nasal decongestants, reserpine, and possibly zinc-based products)
• Head injury
• Lead poisoning
• Nasal or sinus surgery or disease
• Natural aging process
• Radiation therapy
• Recent viral upper respiratory infection
• Tracheostomy
• Tumors of the nose or brain

Images

Smelling

Review Date: 09/09/2009
Reviewed By: Linda J. Vorvick, MD, Medical Director, MEDEX Northwest Division of Physician Assistant Studies, University of Washington, School of Medicine; Seth Schwartz, MD, MPH, Otolaryngologist, Virginia Mason Medical Center, Seattle, Washington. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org)