Smell Disorders

Smell Disorders - Causes and Prevention

Problems with smell happen for many reasons, some clearer than others. Loss of smell may be permanent or temporary, depending on the cause.

As with vision and hearing, people gradually lose their ability to smell as they get older. Smell that declines with age is called presbyosmia and is not preventable. Age is only one of the many reasons that problems with smell can occur. Some people are born with a poor sense of smell, but this is not the case for most people. Most people who develop a problem with smell have recently had an illness or injury. The most common causes are the common cold and chronic nasal or sinus disease.

Other common causes of smell disorders are:

You can help prevent problems with smell caused by respiratory infections and colds by washing your hands frequently, especially during the winter months. Hand washing helps protect you from getting respiratory infections and colds.

If your smell disorder is caused by allergies, you should avoid allergens, like ragweed, grasses, and pet dander. Also, get a flu shot every year to prevent influenza and other serious respiratory conditions that can result from the flu.

Loss of smell can be caused by nasal polyps, which are small, non-cancerous growths in the nose or sinuses that can block the ability of aromas to reach nerve cells high up in the nose. Removing the polyps may restore smell. In rare cases, benign non-malignant tumors grow on the nerves of smell, causing a loss of smell.

Previous surgery or trauma to the head can upset your sense of smell because the nerves that are involved in smell may be cut, blocked, or damaged by scar tissue. Automobile accidents are among the most frequent causes of trauma to the head. Everyone should wear a seat belt, and those who participate in sports, such as bicycling, should wear protective helmets.

People with head and neck cancers who receive radiation treatment to the nasal regions are among those who experience problems with their sense of smell. Older people who have lost their larynx or voice box commonly complain of poor ability to smell and taste.

Tobacco smoking is the most concentrated form of pollution that most people are exposed to. It impairs the ability to identify odors. Quitting smoking is one thing you can do right now to prevent loss of smell and improve your sense of smell. Sometimes exposure to certain chemicals, such as insecticides and solvents, and some chemicals found in the workplace can decrease the sense of smell. Avoid contact with these substances, or if you do come in contact with them, see your doctor.

If you are taking certain medicines, you may notice a change in your ability to smell. Certain antibiotics, some blood pressure pills, some cholesterol-lowering drugs, and some antifungal medications can cause problems with smell. This occurs rarely, but it can happen. If you are taking these medications and notice a change in your sense of smell, talk to your doctor. You may be able to adjust or change your medicine to one that will not cause a problem with smell. Sometimes it is difficult to determine if the cause of the smell disorder is the medication or the underlying condition.

Other less common causes of smell disorders are thyroid abnormalities and vitamin deficiencies. Malnutrition and diabetes also can be linked to smell disorders. If you have any of these conditions and experience a loss of smell or taste, tell your doctor. In some cases, when the condition that is causing the problem with smell is treated, the sense of smell returns.

Sometimes a problem with smell can be a sign of a more serious health problem, such as diseases of the nervous system, like multiple sclerosis, or, in rare cases, a brain tumor. Loss of smell may be the first sign that something is wrong. Check with your doctor if you've been experiencing a problem with your sense of smell for a while. You may be able to prevent or get early treatment for a more serious health problem.

Symptoms and Diagnosis

There are several types of smell disorders depending on how the sense of smell is affected. People who have smell disorders experience either a loss in their ability to smell or changes in the way they perceive odors.

Some people have hyposmia, which occurs when their ability to detect odor is reduced. This smell disorder is common in people who have upper respiratory infections or nasal congestion. This is usually temporary and goes away when the infection clears up.

Other people can't detect odor at all, which is called anosmia. This type of smell disorder is sometimes the result of head trauma, usually from an automobile accident. It can sometimes be caused by aging. In rare cases, anosmia is inherited.

Sometimes a loss of smell can be accompanied by a change in the perception of odors. This type of smell disorder is called dysosmia. Familiar odors may become distorted, or an odor that usually smells pleasant instead smells foul. Sometimes people with this type of smell disorder also experience headaches, dizziness, shortness of breath, or anxiety.

Still others may perceive a smell that isn't present at all, which is called phantosmia.

If you think you have a problem with your sense of smell, try to identify and record the circumstances surrounding it. Ask yourself the following questions:

Ask yourself these questions:

Bring this information with you when you visit your physician. Also, be prepared to tell him about your general health and any medications you are taking. The correct diagnosis by a trained health professional can provide reassurance that your problem with smell is not imaginary.

Your doctor may refer you to an otolaryngologist, or specialist in diseases of the ear, nose, and throat. After a complete medical history and physical examination, your doctor may run special tests to determine the extent and nature of your smell disorder.

Some tests measure the smallest amount of odor you can detect. You also may receive an easily administered "scratch and sniff" test -- that is commercially available to doctors -- to determine how well you can identify various odors from a list of possibilities.

Your doctor may ask you to compare the smells of different chemicals, or to indicate how much the intensity of the smell grows when its chemical concentration is increased. By using these tests, your doctor can determine if you have hyposmia, anosmia, or another type of smell disorder.

In some cases, your doctor may need to perform a nasal examination with a nasal endoscope, an instrument which illuminates and magnifies the areas of the nose where the problem may exist. This test can help identify the area and extent of the problem and help your doctor select the right treatment.

If your doctor suspects that the nerves of smell or other parts of the nose and head that can't be seen by an endoscope are involved, he or she may order an X-ray, usually a CAT scan, to look further into the nose and sinuses.

If you think you have a smell disorder, see your doctor. Diagnosis of a smell disorder is important because once the cause is found, your doctor may be able to treat your smell disorder. Many types of smell problems are reversible, but if they are not, counseling and self-help techniques may help you cope.

This informative article from the NIH has been reprinted here to enlighten you on smell disorders. We at All-About-Noses.com have no medical expertise on this subject.

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