- How does our sense of smell work?
- What are the smell disorders?
- What causes smell disorders?
- How are smell disorders diagnosed?
- Are smell disorders serious?
- Can smell disorders be treated?
- What research is being done?
- What can I do to help myself?
- Find a local Ear, Nose, & Throat Doctor in your town
Smell disorder facts*
*Smell disorder facts by John P. Cunha, DO, FACOEP
- People who experience smell disorders experience either a loss in their ability to smell or changes in the way they perceive odors.
- Hyposmia is when the ability to detect odor is reduced. Anosmia is when a person can't detect odor at all. Some people experience change in the perception of odors, or notice that familiar odors become distorted, or may perceive a smell that isn't present at all.
- Smell disorders have many causes including illness such as upper respiratory infection, injury, polyps in the nasal cavities, sinus infections, hormonal disturbances, dental problems, exposure to certain chemicals such as insecticides and solvents, some medicines, and radiation due to head and neck cancers.
- Obesity, diabetes, hypertension, malnutrition, Parkinson's disease, Alzheimer's disease, multiple sclerosis, and Korsakoff's psychosis are all accompanied or signaled by chemosensory problems like smell disorders.
- There is no specific treatment for smell disorders. If the cause is due to medication, adjusting or changing the drug may relieve symptoms. If an underlying illness causes the smell disorder, when that illness resolves or is treated the sense of smell usually returns. Surgery can remove nasal polyps.
Every year, thousands of people develop problems with their sense of smell. In fact, more than 200,000 people visit a physician each year for help with smell disorders or related problems. If you experience a problem with your sense of smell, call your doctor. This fact sheet explains smell and smell disorders.
Many people who have smell disorders also notice problems with their sense of taste.
How does our sense of smell work?
The sense of smell is part of our chemical sensing system, or the chemosenses. Sensory cells in our nose, mouth, and throat have a role in helping us interpret smells, as well as taste flavors. Microscopic molecules released by the substances around us (foods, flowers, etc.) stimulate these sensory cells. Once the cells detect the molecules they send messages to our brains, where we identify the smell.
Olfactory, or smell nerve cells, are stimulated by the odors around us--the fragrance of a gardenia or the smell of bread baking. These nerve cells are found in a small patch of tissue high inside the nose, and they connect directly to the brain. Our sense of smell is also influenced by something called the common chemical sense. This sense involves nerve endings in our eyes, nose, mouth, and throat, especially those on moist surfaces. Beyond smell and taste, these nerve endings help us sense the feelings stimulated by different substances, such as the eye-watering potency of an onion or the refreshing cool of peppermint.
It's a surprise to many people to learn that flavors are recognized mainly through the sense of smell. Along with texture, temperature, and the sensations from the common chemical sense, the perception of flavor comes from a combination of odors and taste. Without the olfactory cells, familiar flavors like coffee or oranges would be harder to distinguish.
Viewers share their comments
Find out what women really need.