CausesBy Mayo Clinic staff
The common cold is the usual cause for a partial, temporary loss of smell; this will clear up on its own. Any obstruction in the nasal passages, such as polyps, also may cause at least a partial loss of smell. Aging, or even a brain tumor, may cause a complete and permanent loss of smell.
Problems with the inner lining of your nose
Anosmia can be caused by temporary or permanent irritation, or destruction of the mucous membranes lining the inside of your nose. This can be caused by:
These conditions are generally the most common causes of loss of smell.
Obstructions of your nasal passages
Anosmia can be caused by something physically blocking the flow of air through your nose. These obstructions can include:
- Bony deformity inside your nose
- Nasal polyps
Damage to your brain or nerves
Your olfactory system, which provides your sense of smell, consists of receptors in the mucous lining of your nose that send information through nerves into your brain. You can lose your sense of smell if any part of the olfactory pathway is damaged or destroyed. This can happen as a result of:
- Alzheimer's disease
- Brain aneurysm
- Brain surgery
- Brain tumor
- Chemical exposures to certain insecticides or solvents
- Hormonal disturbance
- Huntington's disease
- Kallmann's syndrome (inability of testicles to produce sperm)
- Klinefelter syndrome
- Korsakoff's psychosis (a brain disorder caused by the lack of thiamin)
- Medications (for example, some high blood pressure medications)
- Multiple sclerosis
- Multiple system atrophy (MSA)
- Paget's disease of bone
- Parkinson's disease
- Pick's disease (a form of dementia)
- Radiation therapy
- Sjogren's syndrome
- Traumatic brain injury
- Zinc deficiency
Causes shown here are commonly associated with this symptom. Work with your doctor or other health care professional for an accurate diagnosis.
- Mann NM, et al. Anatomy and etiology of taste and smell disorders. http://www.uptodate.com/home/index.html. Accessed Nov. 15, 2010.
- NIH senior health: Problems with smell. National Institute on Deafness and Other Communication Disorders. http://nihseniorhealth.gov/problemswithsmell/aboutproblemswithsmell/01.html. Accessed Nov. 15, 2010.
- Smell and taste abnormalities. The Merck Manuals: The Merck Manual for Healthcare Professionals. http://www.merckmanuals.com/professional/sec08/ch089/ch089f.html. Accessed Nov. 15, 2010.
- Smell disorders. National Institute on Deafness and Other Communication Disorders. http://www.nidcd.nih.gov/health/smelltaste/smell.asp. Accessed Nov. 15, 2010.
- Olfactory dysfunction. In: Lalwani AK. Current Diagnosis & Treatment in Otolaryngology - Head & Neck Surgery. 2nd ed. New York, N.Y.: The McGraw-Hill Companies; 2008. http://www.accessmedicine.com/content.aspx?aid=2824607. Accessed Nov. 16, 2010.
- Klinefelter syndrome. National Institute of Child Health and Human Development. http://www.nichd.nih.gov/health/topics/klinefelter_syndrome.cfm. Accessed Nov. 15, 2010.
- Kallman syndrome. Genetics Home Reference. http://ghr.nlm.nih.gov/condition/kallmann-syndrome. Accessed Nov. 15, 2010.
- Wernicke-Korsakoff syndrome information page. National Institute of Neurological Disorders and Stroke. http://www.ninds.nih.gov/disorders/wernicke_korsakoff/wernicke-korsakoff.htm. Accessed Nov. 16, 2010.
- Information for patients about Paget's disease of bone. National Institute of Arthritis and Musculoskeletal and Skin Diseases. http://www.niams.nih.gov/Health_Info/Bone/Pagets/patient_info.asp. Accessed Nov. 16, 2010.
- Frontotemporal dementia information page. National Institute of Neurological Disorders and Stroke. http://www.ninds.nih.gov/disorders/picks/picks.htm. Accessed Nov. 16, 2010.
- Multiple system atrophy with orthostatic hypotension information page. National Institute of Neurological Disorders and Stroke. http://www.ninds.nih.gov/disorders/msa_orthostatic_hypotension/msa_orthostatic_hypotension.htm. Accessed Nov. 16, 2010.
- Sjogren's syndrome. American College of Rheumatology. http://www.rheumatology.org/practice/clinical/patients/diseases_and_conditions/sjogrens.asp. Accessed Nov. 16, 2010.