Why Is My Nose So Sensitive to Smells? We Explain How It Works

JAN 31, 2023 AT 08:37 AM

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If you suddenly are (or always have been) super sensitive to smells, you may be a ‘super smeller’. Unlike most of the population, you are likely to feel very uncomfortable or even nauseous when you come across unpleasant smells. Similarly, it could be that lovely smells, e.g., bakeries, stir up strong positive emotions.

If you are wondering why your nose is so sensitive, this article will provide you with all the answers modern science offers. Your condition is medically referred to as hyperosmia. This medical term refers to people whose sense of smell is much more heightened than an average person's.

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Depending on the type and cause of your hyperosmia, you may be more sensitive to pleasant or unpleasant scents. Though hypersomnia is rare, researchers have pinpointed some of its causes and how it is likely to affect your life.

Understanding Hyperosmia

People with hyperosmia may also notice a change in their sense of taste. The olfactory system connects the senses of smell and taste. This connection causes a sharp sense of smell to intensify flavors. Your olfactory system is located in your nose. All scents travel through here before passing to your throat. If the smell is intense, you may "taste it in your throat" and feel nauseous.

Effects of Hyperosmia

Anyone suffering from hyperosmia knows it can significantly affect your day-to-day life and well-being. You cannot go to certain places or run specific errands, e.g., filling up your car at the gas station. Foods with strong smells will also be off your menu. This may affect your nutrition, especially if the condition lasts for a long time.

If your smell sensitivity persists for a long and begins to impact your life, you are well advised to consult an ENT specialist.

Causes of Hyperosmia

1. Underlying Health Conditions

An underlying health condition is the most likely cause of hyperosmia that develops gradually. Several studies have linked hyperosmia to health conditions like migraines, Lyme disease, hormone deficiency, and body fluid abnormalities.

Research has yet to pinpoint how these conditions result in hyperosmia. The most popular thesis is that these diseases disrupt your body’s electrolytes and affect the signals your scent receptors generate.

Neurological and autoimmune diseases are more likely to cause hyperosmia. Neurological conditions, especially those that affect your mid-temporal lobe (which stores memories), are the most likely to cause hyperosmia. These conditions may cause a false but very realistic strong odor. Most people know that an olfactory hallucination is a precursor to suffering a seizure.

These are the neurological conditions that have been conclusively linked to hyperosmia:

  • Epilepsy
  • Parkinson’s disease
  • Multiple sclerosis
  • Alzheimer’s
  • Tumors or polyps in the skull or nose

2. Prescription medications

Your sense of smell may have heightened due to a prescription medication you are on. Though most medications usually reduce the sense of smell, occasional ones may heighten your smell.

If your heightened sense of smell began shortly after taking new prescription medication, it is advisable to consult your doctor. They will rule out or finger the medication as the cause of your sudden sensitivity to smells.

3. Genetic conditions

Some people are genetically predisposed to have a better sense of smell than others. Multiple studies have revealed that overexpression or duplication of the KAL1 gene results in hyperosmia. This gene produces a protein that controls the growth and development of nerve cells that process smell.

Other genetic mutations have also been linked to super smellers. A study revealed that genetic coding varies in a population for the protein that binds onto smells to assist them in reaching your olfactory region. This is why some people naturally have a sharper sense of smell than others.

4. Pregnancy

Pregnant women can testify to increased smell sensitivity. As soon as the bun starts growing in the oven, you will likely find smells you could easily ignore have become nauseatingly revolting. Studies have proven that many pregnant women temporarily acquire super smeller status.

Researchers relied on more than fifty studies to conclude that pregnant women are more sensitive to particular smells but do not have an overall increased smell intensity. The studies did not have sufficient evidence to prove whether or not pregnant women had a better ability to identify different scents.

Researchers are still keen on discovering why this commonly reported temporary smell sensitivity occurs.

5. Brain Differences

In 2019, a study that investigated whether the brains of people suffering from hyperosmia were different from those who did not have the condition was published. Researchers used brain scans o compare the brains of men who were super smellers against those with an ordinary sense of smell. The scientists focused on the volume of the brain's grey matter part associated with smell.

The results proved that people with hyperosmia had higher brain activity in the areas associated with the sense of smell—particularly the learning and recall of smells. Though scientists successfully identified the differences, they could not determine whether they were learned or caused by genetics.

6. The evolutionary link between memory and smell

A different study suggested that the vital link between memory and smell is to blame for hyperosmia. Fifty-five volunteers who identified as super smellers participated in the study. They were compared to people of a similar age and gender who had an average sense of smell.

The groups filled in structured questionnaires inquiring into their experiences regarding environmental smells. Participants quickly linked specific smells to unpleasant memories and negative consequences. Such odors .g. human sweat and formaldehyde, were found to stir up feelings of discomfort, disgust, and annoyance. The researchers proposed that sensitivity to these smells was developed based on negative experiences, e.g., at the workplace.                  

7. Training and Conditioning

Typically, our ability to identify a smell depends on the smell's concentration in our environment. Super smellers have a low threshold and can detect smells at a low concentration. Most people do not have the ability to pick up on smells that are lowly concentrated.

Two hundred and thirty volunteers participated in the study, where they were exposed to mint-like eucalyptus and rose-like phenyl ethyl alcohol. The researchers built a custom machine that tested the participants using eight concentrations of the smells ranging from very strong to barely detectable.

The results found that two percent of the participants demonstrated the hyperosmic phenomenon in the first round of testing. After repeated testing, another 10% of the population developed hyperosmia when they were tested weekly. It was found that the participants could then detect smells that were three ranges below their initial capability. This learned capability lasted throughout the ten-week duration of the study was performed.

The researchers also noted that the participants suffered a sudden reduction of smell detection on the lower end of the threshold. They gave solid evidence of how people could train themselves to be short-term super-smellers. The principles of smell training have also been used to help people who lost their sense of smell recover.

Treatment

Hyperosmia treatment is entirely dependent on its cause. A typical temporary relief is to carry around a piece of peppermint candy or gum. When you come across a triggering smell, use peppermint to distract your olfactory system from the offensive smell. Consult your doctor about your hyperosmia to find the most effective treatment for your cause.

Usually, treating the condition that causes hyperosmia reduces its severity. If your hyperosmia is caused by migraines, taking medications that prevent the migraines may help reduce the hyperosmia. Patients with tumors in the skull or nose usually need surgery to cure hyperosmia.

Conclusion

A wide range of factors can cause Hyperosmia or super-smelling. Some people are just born that way. Their genetic conditioning makes their sense of smell superior to that of ordinary people. Others become temporary super smellers due to illness, pregnancy, or taking certain prescription medications.