Smell - impaired
Loss of smell; Anosmia; Hyposmia; Parosmia
Impaired smell is the partial or total loss or abnormal perception of the sense of smell.
Considerations
The loss of smell can occur with conditions that prevent air from reaching smell receptors located high in the nose, or loss of or injury to the smell receptors. Loss of smell is not serious, but can sometimes be a sign of a nervous system 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.
Allergies
An allergy is an immune response or reaction to substances that are usually not harmful.
Allergic rhinitis
Allergic rhinitis is a diagnosis associated with a group of symptoms affecting the nose. These symptoms occur when you breathe in something you are ...
Some loss of smell occurs with aging. In most cases, there is no clear cause, and there is no treatment.
The sense of smell also enhances your ability to taste. Many people who lose their sense of smell also complain that they lose their 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. You may feel rather than smell them.
Causes
Loss of smell can be caused by:
- Medicines that change or decrease the ability to detect odors (such as amphetamines, estrogen, naphazoline, phenothiazines, long-term use of nasal decongestants, reserpine, and possibly zinc-based products)
- Blockage of the nose due to nasal polyps, nasal septal deformities, and nasal tumors
- Infections in nose, throat, or sinuses
- Allergies
- Endocrine disorders
- Dementia or other neurological problems
- Nutritional deficiencies
- Head injury or nasal or sinus surgery
- Radiation therapy to head or face
Home Care
Treating the cause of the problem may correct the lost sense of smell. Treatment can include:
- Antihistamines (if the condition is due to an allergy)
- Changes in medicine
- Surgery to correct blockages
- Treatment of other disorders
Avoid using too many nasal decongestants, which can lead to repeated nasal congestion.
If you lose your sense of smell, you may have changes in taste. Adding highly seasoned foods to your diet can help stimulate the taste sensations that you still have.
Improve your safety at home by using smoke detectors and electric appliances instead of gas ones. You may not be able to smell gas if there is a leak. Or, install equipment that detects gas fumes in the home. People with smell loss should label when the food item was opened to prevent eating spoiled food.
Safety at home
Smoke alarms or detectors work even when you cannot smell smoke. Tips for proper use include:Install them in hallways, in or near all sleeping areas...
There is no treatment for loss of smell due to aging.
If you have a loss of smell due to a recent upper respiratory infection, be patient. The sense of smell may return to normal without treatment.
When to Contact a Medical Professional
Call your health care provider if:
- The loss of smell continues or is getting worse
- You have other unexplained symptoms
What to Expect at Your Office Visit
The provider will perform a physical exam and ask questions about your medical history and current symptoms. Questions may include:
- When did this problem develop?
- Are all odors affected or only some? Is your sense of taste affected?
- Do you have cold or allergy symptoms?
- What medicines do you take?
- Do you have any other symptoms?
The provider will look at and around your nose. Tests that may be performed include:
-
CT scan
CT scan
A computed tomography (CT) scan is an imaging method that uses x-rays to create pictures of cross-sections of the body. Related tests include:Abdomin...
-
MRI scan
MRI scan
A head MRI (magnetic resonance imaging) is an imaging test that uses powerful magnets and radio waves to create pictures of the brain and surrounding...
-
Nasal
endoscopy
Endoscopy
Endoscopy is a way of looking inside the body using a flexible tube that has a small camera and light on the end of it. This instrument is called an...
- Olfactory nerve testing
- Smell testing
If the loss of sense of smell is caused by a stuffy nose (nasal congestion), decongestants or antihistamines may be prescribed.
Other treatments for a stuffy nose may include:
- A vaporizer or humidifier may help keep mucus loose and moving.
- Steroid nasal sprays or pills may be recommended.
- Vitamin A may be given by mouth or as a shot.
-
Nasal steroid sprays
may be prescribed.
Nasal steroid sprays
Steroid nasal sprays; Allergies - nasal corticosteroid sprays
References
Baloh RW, Jen J. Smell and taste. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine . 25th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 427.
Leopold DA, Holbrook EH. Physiology of olfaction. In: Flint PW, Haughey BH, Lund LJ, et al, eds. Cummings Otolaryngology: Head & Neck Surgery . 6th ed. Philadelphia, PA: Elsevier Saunders; 2015:chap 39.
Review Date: 8/5/2015
Reviewed By: Sumana Jothi MD, specialist in laryngology, Clinical Instructor UCSF Otolaryngology, NCHCS VA, SFVA, San Francisco, CA. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.