Causes of Poor Sense of Smell
People have generally a poor sense of smell as they age.
A cold or allergies can cause a decrease in your sense of smell. This is because the inflammation that occurs during an infection or allergy blocks some nasal passages, making it harder to detect odors. After the infection goes away, it may take several weeks for your sense of smell to become normal again.
If you had more than one sinus infection within six months, see your doctor for treatment of recurring infections. He might prescribe antibiotics designed to kill the bacteria causing chronic sinusitis and prevent further infections. As part of his treatment plan, he will recommend surgery to open up the blocked sinuses and make them drain more easily.
Smoking, as well as secondhand smoke, can impact your sense of smell and taste. Over time, it leads to a condition called “smoker’s nose,” where the area inside the nose becomes pale white from lack of oxygen.
The longer you’ve been smoking, the worse your sense of smell will be. Heavy smokers have difficulty distinguishing between flavors as the number of receptor cells decreases by 40 percent over 10 years of heavy smoking.
In rare cases, anosmia is caused by a genetic disorder that impedes the proper functioning of neurons that transmit odor signals to your brain or other health conditions such as’s disease.
5. Dust, fumes, and other environmental pollutants:
Exposure to chemicals such as pesticides and solvents can also harm your sense of smell.
6. Neurological conditions:
Alzheimer’s disease and Parkinson’s disease cause the brain to stop producing the neurotransmitter dopamine, which among other things helps you detect odors. When your ability to smell is impaired, food may taste bland or unpleasant.
Because people with these diseases also have a poor appetite, weight loss becomes a problem. Parkinson’s disease patients tend to die an average of 5 to 10 years after the onset of symptoms, usually, because of pneumonia.
7. Normal aging:
Some older people experience a loss in their sense of smell due to normal aging changes in the nose and brain.
8. Physical trauma:
Injury or nasal surgery can damage or destroy your olfactory nerve (the nerve that carries signals from your nose to your brain) and result in permanent anosmia. Even a severe injury to your head could affect both smell and taste if damage occurs at the point where the first cranial nerve (a major nerve responsible for sensation in parts of your face including your nose) leaves the skull to travel through the sinus cavity, past the back of the throat and the voice box to reach your tongue.
Some drugs can cause a decrease in your sense of smell, including certain antibiotics, antidepressants, antihistamines, decongestants nasal sprays, opioid painkillers, sedatives, and antipsychotic medications.
In most cases, symptoms will clear up when you stop taking them or when you lower the dosage. However, if you have been taking a medication for an extended period it is best to see your doctor before stopping as sudden withdrawal could cause other symptoms such as headaches insomnia blurred vision.
10. Medical conditions:
Other medical conditions that may affect your sense of smell include: diabetes head injury nasopharyngeal cancer sinusitis exposure to toxic chemicals or radiation.
11. Nasal polyps:
Small, grape-like swellings that usually appear in the lining of the nose are called nasal polyps. They occur due to chronic inflammation and are common among people who have asthma or cystic fibrosis.
The polyps can also prevent your sense of smell from properly functioning because they block airflow through your nasal passages. However, if you treat the underlying condition, the polyps will most likely go away on their own within a few months to a year.
12. Chemical irritation:
If something gets into your nose and irritates it, causing a runny nose and postnasal drip (the sensation that mucus is flowing down the back of your throat), then this can temporarily interfere with your ability to smell.
13. Substance abuse:
Alcohol and recreational drugs such as cocaine, ecstasy, methamphetamine, and marijuana have been known to affect your sense of smell as well as cause damage to the nasal tissues that may result in permanent anosmia for some users.
14. Hypertrophic osteoarthropathy:
In this condition, swelling occurs in the bones and tissues lining the sinuses due to a thickening of the tissue near the nostrils, which can cause obstruction of airflow through your nose and interfere with your sense of smell. Known more commonly as Puffy Nose Syndrome it is a rare condition associated with uncontrolled thyroid disease or multiple myeloma (a type of blood cancer).
15. Sjogren’s syndrome:
This disease is an autoimmune disorder in which your body’s white blood cells attack the moisture-producing glands. In Sjogren’s syndrome, these glands are mostly found in your eyes and mouth but also may be located in the nose. The resulting dryness of the eye and mouth can cause a reduction or loss of your ability to taste as well as to smell, making food seem dull and less appetizing.
16. Cholinergic urticaria:
People with this rare type of hives tend to have severe itching or burning sensations all over their bodies after being exposed to certain triggers such as heat stress, hot showers, spicy foods, alcohol intake, caffeine ingestion, etc. In some cases, these symptoms can occur simply from exposure to fragrances from perfume, a household cleaner, or lotion.
Also known as radiotherapy, the treatment is often used in conjunction with surgery to help destroy cancer cells and shrink tumors before you have chemotherapy. It can sometimes damage your olfactory nerve cells located at the back of your nose and lead to anosmia, although this side effect is usually temporary if it occurs at all.
In some cases, for example for certain head and neck cancers, radiotherapy may be given through tiny beams aimed directly into affected areas without affecting other parts of your body so trying to treat the problem from another angle such as by using chemo or surgery might correct any smell loss that has occurred due to radiotherapy alone.
This condition causes inflammation of your nasal passages, which can lead to thick nasal mucus that blocks the passage of air through your nose and decreases your sense of smell.
It often occurs as a result of an underlying cold or flu but may also be caused by allergies, an irritant such as second-hand cigarette smoke, dust or chemical fumes, living in polluted areas, or working with strong odors daily. You are more likely to develop rhinitis if you have asthma or hay fever too
Poor sense of smell and taste:
a. Deficiency of vitamin B12:
Vitamin B12 deficiency can be diagnosed by performing blood tests to determine the level of folate. Anemia usually accompanies Vitamin B12 deficiency, which is characterized by decreased hemoglobin, low mean corpuscular volume, and low mean corpuscular hemoglobin.
b. Diabetes mellitus:
The neurological manifestations of diabetes include peripheral neuropathy, mononeuropathy multiplex, cranial nerve damage (i.e., oculomotor palsy), polyneuropathy, autonomic dysfunction, plexopathy, mononeuritis multiplex,*arrhythmia*, encephalopathy/dementia syndrome, etc.
c Head injury:
loss of olfaction follows an impact to the head because the cribriform plate is extremely sensitive to direct blows or fractures which would see a sudden loss of sense of smell. The ability to taste food also goes as this part of the brain is closely linked to the olfactory system.
Born with a poor sense of smell:
a. Primary ciliary dyskinesia(Kartagener Syndrome):
Primary ciliary dyskinesia, sometimes known as Kartagener syndrome, is a genetic disorder that results in being unable to move mucus out of the lungs or other organs because one or more of your cilia are defective.
b. Cystic Fibrosis:-
Cystic fibrosis is a serious hereditary disease often leading to problems with respiratory health and fertility in men. It occurs when both parents pass along flawed copies of the cystic fibrosis transmembrane conductance regulator gene to their offspring.
When an individual has two mutated copies of this gene it leads to very viscous secretions within the respiratory system which can cause bronchoconstriction, chronic cough with oral yeast infections, and reduced fertility.
c. Cone-Rod dystrophy:
Cone-rod dystrophy is an inherited condition that begins in childhood or adolescence and usually progresses until the third decade of life. It affects both eyes equally but may vary in severity from mild to severe forms. Early symptoms include deteriorating night vision and loss of peripheral (side) vision
d. Parkinson’s Disease:
Parkinson’s disease damages a part of the brain called the substantia nigra which helps control movement by producing dopamine, a chemical messenger associated with thoughts of reward. Damage to this area causes a severe drop in dopamine levels leading to tremors, slow movements, walking, and changes in the sense of smell or loss of it completely.
e. Alzheimer’s Disease:
Alzheimer’s disease is a neurodegenerative disorder that results in severe memory loss, confusion, mood swings, and changes in behavior all due to the death of brain cells. Although scientists are still trying to determine what causes this disease there are molecules known as Amyloid-B plaques that have been found in the brains of those who have had Alzheimer’s disease. These plaques cause inflammation within the brain which can lead to degeneration of nerve cells resulting in cognitive decline.
f. Parkinson Disease:
People with Parkinson’s disease have low dopamine levels in the basal ganglia, a part of the brain that controls movement. This leads to tremors, muscle rigidity, slowed movements and changes involuntary movement. It might also result in problems with thinking and memory as well as depression or anxiety