Introduction:
Our sense of smell & taste helps us enjoy life. We delight in the aromas of our favorite foods or the fragrance of flowers. Our sense of smell also is a warning system, alerting us to danger signals such as a gas leak, spoiled food, or a fire. Any loss in our sense of smell can have a negative effect on our quality of life. It also can be a sign of more serious health problems.
Roughly 1–2 percent of people in North America say that they have a smell disorder. Problems with smell increase as people get older, and they are more common in men than women. In one study, nearly one-quarter of men ages 60–69 had a smell disorder, while about 11 percent of women in that age range reported a problem.
Many people who have smell disorders also notice problems with their sense of taste.
CLICK & SEE
Other Names:
Loss of smell; Anosmia.
CLICK & SEE
How do we smell?
Our sense of smell—like our sense of taste—is part of our chemosensory system, or the chemical senses 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....CLICK & SEE
Types of smell disorders:
People who experience smell disorders experience either a loss in their ability to smell or changes in the way they perceive odors. As for loss of the sense of smell, some people have hyposmia, which is when their ability to detect odor is reduced. Other people can’t detect odor at all, which is called anosmia. As for changes in the perception of odors, some people notice that familiar odors become distorted. Or, an odor that usually smells pleasant instead smells foul. Still other people may perceive a smell that isn’t present at all.You may click to see :Smell Dysfunction Glossary of Terms….
Sniff Test May Signal Disorders’ Early Stages ….
Symptoms:
Smell disorder symptoms are : Reduced sense of smell, Anosmia, Olfactory dysfunction, Loss of smell, Lack of sense of smell in children, Paraosmia due to amebic meningitis or other types.
There are various symptoms related to “smell”. Having a particular smell or odor can be a serious symptom. There are various odor symptoms such as body odor, urine odor, stool odor, and other odor symptoms. The sense of smell can be subject to loss of smell, loss of taste, or other nose symptoms….
Considerations:
The loss of smell can occur as a result of nasal congestion or blockage of the nose and isn’t serious, but it can sometimes be a sign of a nervous system (neurological) condition.
Temporary loss of the sense of smell is common with colds and nasal allergies, such as hay fever (allergic rhinitis). It may occur after a viral illness.
Some loss of smell occurs with aging. In most cases, there is no obvious or immediate cause, and there is no treatment.
The sense of smell is often lost with disorders that prevent air from reaching the part of the nose where smell receptors are located (the cribriform plate, located high in the nose). These disorders may include nasal polyps, nasal septal deformities, and nasal tumors.
Other disorders that may cause a loss of the sense of smell include:
The sense of smell also enhances your ability to taste. Many people who lose their sense of smell also complain of a loss of the sense of taste. Most can still tell between salty, sweet, sour, and bitter tastes, which are sensed on the tongue. They may not be able to tell between other flavors. Some spices (such as pepper) may affect the nerves of the face and may be felt rather than smelled.
Causes:
Smell disorders have many causes, with some more obvious than others. Most people who develop a smell disorder have experienced a recent illness or injury. Common causes of smell disorders are:
*Disorders of the endocrine system
*Head trauma
*Nervous disorders
*Nutritional disorders
*Tumors of the head or brain
*Many medications may change or decrease the ability to detect odors.
*Sinus and other upper respiratory infections
*Polyps in the nasal cavities
*Frontal head injuries
*Hormonal disturbances
*Dental problems
*Exposure to certain chemicals, such as insecticides and solvents
*Numerous medications, including some common antibiotics and antihistamines
*Radiation associated with the treatment of head and neck cancers
*Aging
*Other health issues that affect the nervous system, such as Parkinson’s disease or Alzheimer’s disease
In the year 2009, the FDA warned consumers to stop using several popular cold remedies because they could result in the loss of smell. Smoking also can interfere with our sense of smell.
Most people who develop a smell disorder have recently experienced an illness or an injury. Common triggers are upper respiratory infections and head injuries. Some medicines have also been associated with smell disorders. People with head and neck cancers who receive radiation treatment are also among those who experience problems with their sense of smell.
Associated conditions
* Dysosmia
* Kallmann syndrome
* Zinc deficiency
* Cadmium Poisoning
* Holoprosencephaly
* Primary amoebic meningoencephalitis caused by Naegleria fowleri
* Refsum disease
* CHARGE syndrome
* Ageusia
Diagnosis:
Both smell and taste disorders are treated by an otolaryngologist, a doctor who specializes in diseases of the ear, nose, throat, head, and neck. Some tests are designed to measure the smallest amount of odor that patients can detect. Another common test consists of a booklet of sheets that contain tiny beads filled with specific odors.In fact, an easily administered “scratch and sniff” test allows a person to scratch pieces of paper treated to release different odors, sniff them, and try to identify each odor from a list of possibilities. In this way, doctors can easily determine whether patients have hyposmia, anosmia, or another kind of smell disorder.
CLICK & SEE
An accurate assessment of your smell disorder will include, among other things, a physical examination of your ears, nose, and throat; a review of your health history, such as exposure to toxic chemicals or trauma; and a smell test supervised by a health care professional.
Risk Factors:
Like all of our senses, our sense of smell plays an important part in our lives.When smell is impaired, some people change their eating habits. Some may eat too little and lose weight while others may eat too much and gain weight. Food becomes less enjoyable and people may use too much salt to improve the taste. This can be a problem for people with certain medical conditions, such high blood pressure or kidney disease. In severe cases, loss of smell can lead to depression.
The sense of smell often serves as a first warning signal, alerting us to the smoke of a fire or the odor of a natural gas leak and dangerous fumes. Perhaps more important is that our chemosenses are sometimes a signal of serious health problems. 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.
Presentation
Anosmia or smell disorder can have a number of detrimental effects. Patients with sudden onset anosmia may find food less appetizing, though congenital anosmics rarely complain about this. Loss of smell can also be dangerous because it hinders the detection of gas leaks, fire, and spoiled food. The common view of anosmia as trivial can make it more difficult for a patient to receive the same types of medical aid as someone who has lost other senses, such as hearing or sight.
Losing an established and sentimental smell memory (e.g. the smell of grass, of the grandparents’ attic, of a particular book, of loved ones, or of oneself) has been known to cause feelings of depression.
Loss of olfaction may lead to the loss of libido, though this usually does not apply to congenital anosmics.
Often people who have congenital anosmia report that they pretended to be able to smell as children because they thought that smelling was something that older/mature people could do, or did not understand the concept of smelling but did not want to appear different from others. When children get older, they often realize and report to their parents that they do not actually possess a sense of smell, often, to the surprise of their parents.
Zicam controversy
On June 16, 2009, the U.S. Food and Drug Administration sent a warning letter to Matrixx Initiatives, manufacturer of an over-the-counter nasal spray for the common cold, Zicam. The FDA cited complaints that the product caused anosmia. The manufacturer strongly denies these allegations, but has recalled the product and has stopped selling it.
Treatment:
Some people experience relief from smell disorders. Since certain medications can cause a problem, adjusting or changing that medicine may ease its effect on the sense of smell. Others recover their ability to smell when the illness causing their olfactory problem resolves. For patients with nasal obstructions such as polyps, surgery can remove the obstructions and restore airflow. Not infrequently, people enjoy a spontaneous recovery because olfactory neurons may regenerate following damage.
Home Care:
Treating the cause of the problem may correct loss of the sense of smell. Treatment can include:
*Antihistamines (if the condition is related to allergy)
*Changes in medication
*Surgery to correct blockages
*Treatment of other disorders
*Avoid using too many nasal decongestants, which can lead to recurring nasal congestion.
If you lose your sense of smell, you may have changes in taste. But, adding highly seasoned foods to your diet can help stimulate the taste sensations that you still have.
Improve your safety at home by using smoke detectors and electric appliances instead of gas ones. You may not be able to smell gas if there is a leak. Or, install equipment that detects the presence of gas fumes in the home.
There is no treatment for loss of smell due to aging.
If you have a loss of smell due to a recent viral upper respiratory infection, be patient. The sense of smell may return to normal without treatment.
Click to see:–Herbs for Loss of Smell & Taste
Click to learn more about : Treatments for a Loss of Sense of Smell
Research:
The National Institute on Deafness and Other Communication Disorders (NIDCD) supports basic and clinical investigations of smell and taste disorders at institutions across the nation. Some of these studies are conducted at chemosensory research centers, where scientists are making discoveries that help them understand our olfactory system and may lead to new treatments for smell disorders.
Some of the most recent research into our sense of smell is also the most exciting. In 2004, NIDCD grantee Linda B. Buck, Ph.D., together with Richard Axel, M.D., received the Nobel Prize in Physiology or Medicine for their discovery of a family of about 1,000 olfactory receptor genes that encode the receptors found on olfactory sensory neurons—one receptor per neuron. Recent studies on how olfactory sensory neurons recognize odors, aided by new technology, are revealing how our olfactory system detects and identifies the differences between the many chemical compounds that form odors.
Like our sense of taste, our sense of smell can be damaged by certain medicines. However, other medications, especially those prescribed for allergies, may improve the sense of smell. NIDCD-supported scientists are working to find out why this is so in an effort to develop drugs that can help restore a person’s sense of smell.
NIDCD-supported researchers have found that the loss of smell affects the choices an older person makes about eating certain foods. Food choices impact diet and overall health. They are looking at how and why this takes place in order to develop more effective ways to help older people—especially those with chronic illnesses—cope better with problems with smell and to maintain proper nutrition.
Olfactory sensory neurons—as well as sensory cells that help us taste—are the only sensory cells that our bodies regularly replace. Scientists are exploring why and how this happens in order that they might find ways to replace other damaged sensory and nerve cells.
NIDCD-supported chemosensory scientists are exploring how to:
*Promote the regeneration of sensory and nerve cells.
*Understand the effects of the environment (such as gasoline fumes, chemicals, and extremes of relative humidity and temperature) on smell and taste.
*Prevent the effects of aging on smell and taste.
*Prevent infectious agents and toxins from reaching the brain through the olfactory nerve.
*Develop new diagnostic tests for taste and smell disorders.
*Understand associations between chemosensory disorders and altered food intake in aging as well as in various chronic illnesses.
*Improve treatment methods and rehabilitation strategies.
MORE INFORMATION:-
Click For more information NIDCD Information Clearinghouse.
The NIDCD maintains a directory of organizations that can answer questions and provide printed or electronic information about hearing, balance, smell, taste, voice, speech, and language. This directory is available at www.nidcd.nih.gov/directory.
To find organizations with information specifically about smell disorders, click on Smell and Taste in the “Browse by Topic” list.
For more information, additional addresses and phone numbers, or a printed list of organizations, contact:
NIDCD Information Clearinghouse
1 Communication Avenue
Bethesda, MD 20892-3456
Toll-free Voice: (800) 241-1044 begin_of_the_skype_highlighting (800) 241-1044 end_of_the_skype_highlighting
Toll-free TTY: (800) 241-1055
Fax: (301) 770-8977
E-mail: nidcdinfo@nidcd.nih.gov
NIH Publication No. 09-3231
Updated July 2009
Disclaimer: This information is not meant to be a substitute for professional medical advise or help. It is always best to consult with a Physician about serious health concerns. This information is in no way intended to diagnose or prescribe remedies.This is purely for educational purpose.
Resources:
http://health.nytimes.com/health/guides/symptoms/smell-impaired/overview.html
http://www.righthealth.com/topic/Disorders_Smell/overview/healthocrates20?fdid=healthocrates_a1e23a7936222b32cbffcf28f010c155
http://www.medicinenet.com/smell_disorders/article.htm
http://www.wrongdiagnosis.com/sym/smell_symptoms.htm#intro
http://en.wikipedia.org/wiki/Anosmia
