Problems with Smell

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.

Effects of Aging

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.

The Most Common Causes

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 infection.

Swollen sinuses and nasal passages often result in problems with smell because the odors in the air do not have good access to the olfactory sensory cells. These conditions may cause total or partial loss of smell . The problem usually diminishes or goes away when the underlying medical condition clears up. Your doctor may prescribe an antibiotic or anti-inflammatory drug to reduce the nasal swelling. Such treatments often improve your sense of smell.

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.

Other Common Causes

Other common causes of smell disorders are

Head Injuries

Previous surgery or trauma to the head can impair your sense of smell because the olfactory nerves may be cut, blocked, or physically damaged. Automobile accidents are among the most frequent causes of trauma to the face and head. For this reason, everyone should wear a seat belt when riding in a car. People who participate in sports, such as bicycling, should wear protective helmets.

Allergies

If your smell disorder is caused by allergies and seasonal nasal congestion, you should avoid allergens, such as 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.

Exposure to Airborne Toxic Chemicals

Sometimes exposure to certain chemicals, such as insecticides, paint, floor cleaners, and other solvents, and some toxic chemicals found in the workplace can permanently damage the sense of smell. Avoid contact with these substances and wear a respirator, or if you do come in contact with them and experience a problem with your ability to smell, see your doctor.

Medications

If you are taking certain medicines, you may notice a change in your ability to smell. In 2009, the U.S. Food and Drug Administration warned consumers to stop using several popular cold remedies because they could result in the loss of 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. The sense of smell usually returns to normal when you stop taking the medicine.

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.

Nasal Polyps

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 odors to reach olfactory sensory cells high up in the nose. Removing the polyps may restore smell. In rare cases, benign non-malignant tumors grow on the olfactory nerves leading to the brain, causing a loss of smell.

Radiation Treatment

People with head and neck cancers who receive radiation treatment to the nose and mouth regions commonly experience problems with their sense of smell and taste as an unfortunate side effect. Older people who have lost their larynx or voice box commonly complain of poor ability to smell and taste.

Smoking Tobacco

Tobacco smoking is the most concentrated form of pollution that most people are exposed to. It impairs the ability to identify and enjoy odors. Quitting smoking is one thing you can do right now to protect your sense of smell.

Less Common Causes

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. This might include diseases of the nervous system, such as multiple sclerosis, Parkinson's disease, or Alzheimer's disease, 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.