Sense of Smell Loss

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Sense of Smell Loss

Question:

About six months ago I noticed I can't smell common scents like fresh peaches. I have read about the correlation between declining sense of smell and Alzhiemer's disease. My memory has sometimes been faulty for the last few decades. What are the risks of my developing Alzheimer's, and should I consult my doctor about my loss of smell?

Answer:

Two out of three people who lose the ability to smell have had this problem caused by nose or sinus disease or by head trauma. Examples of nose and sinus problems that can result in lost smell (sometimes with long-lasting effects) are nasal polyps, sinus infections, upper respiratory infections, and Sjogren's syndrome (dryness of the mouth, eyes, and nose). Medicines (particularly blood pressure medicines such as beta blocker medicines and ace-inhibitor medicines, or in some cases thyroid medication) are sometimes the cause of changes in smell.

Aging can also result in smell loss—a modest change in your smelling is a normal part of aging, but it is not usually very noticeable. You are correct that Alzheimer's disease can result in noticeable abnormal smelling ability. This is also the case for Parkinson's disease. Changes in smelling occur very gradually in these conditions. For most people with one of these illnesses, problems with smell are not obvious until the neurologic disease has progressed to an advanced stage. About eight years ago, one study explored whether lost smell was a good predictor for dementia. This study followed nearly 2000 older people over two years. The researchers couldn't link diminished smelling (partially the lost sense of smell) with a larger risk for dementia diagnosis during their follow up time, but they did calculate a nearly doubled risk for dementia for people who had complete loss of smell.

It may be helpful for you to review your medical history, medications, and any nasal or sinus symptoms with a doctor.

Mary Pickett, M.D., is a lecturer for Harvard Medical School and an assistant professor of medicine at Oregon Health & Science University in Portland, OR. At OHSU, she practices general internal medicine and teaches medical residents and students.

Last updated:	July 20, 2009