Condition Basics

What is anosmia?

Anosmia (say "ay-NAWZ-mee-uh") is the loss of the sense of smell. It can be a problem by itself or a symptom of another health problem. It can last a short time, such as when you have a stuffy nose from a cold, or it can be permanent.

Some people have a reduced sense of smell. This is called hyposmia (say "hy-PAWZ-mee-uh"). These people may be able smell some scents but not others. Or scents may smell different than they used to.

How can it affect your life?

The sense of smell is closely tied to the sense of taste. If you can't smell the aroma of food, you will likely have trouble tasting food. This could lead to not eating enough and losing weight. You also may not get the nutrients you need.

Anosmia can affect your mood. It can make you feel sad or depressed, because the aromas of food, flowers, and other things add to the joy of life.

Lack of a sense of smell also can be dangerous. For example, you wouldn't be able to smell a gas leak or smoke from a fire.

What causes it?

Many people lose some of their sense of smell or taste as they get older. But lack of the sense of smell is usually caused by an injury or a health problem. Anosmia can be short-term and get better when the health problem goes away. But sometimes it's permanent.

Anosmia can be caused by:

• Colds or sinusitis.
• Seasonal allergies.
• Smoking cigarettes.
• Some medicines.
• Head injuries.
• Some brain problems, such as a stroke, Alzheimer's disease, or a tumour.

How is it diagnosed?

A doctor diagnoses lack of the sense of smell with:

• A family and personal history.
• An examination of the head, neck, and nose.

In some cases, you also may have:

• Tests to see if you can smell certain scents or odours.
• A blood test to look for a vitamin deficiency or other health problem.
• An MRI or a CT scan to look for problems in your brain.

How is anosmia treated?

Treatment depends on whether the cause is something that can get better on its own or be fixed. Your sense of smell should return if, for example, a cold that caused your loss of ability to smell gets better or if you stop taking a medicine that caused you to not be able to smell.

If an injury, disease, or surgery caused damage to the nerves that control your sense of smell, you might not be able to smell again. Or your sense of smell might return, but it may be different than it was before. Sometimes the sense of smell will return on its own.