Introduction

What is chronic anosmia?

Anosmia is a condition where a person loses their sense of smell either temporarily or permanently. It can occur when something blocks or damages the olfactory system (the system responsible for detecting and processing smells).³ Anosmia is considered chronic when the loss of smell goes on for a long time, showing little to no signs of improving even when taking treatment. 

Understanding the sense of smell

Basic Biology

It is useful to know how we detect smells. Smelling begins when something in the air has a smell like perfume or smoke, tiny particles called molecules are given off. The molecules are then inhaled in through the nose. When inhaled, the molecules travel up through the nasal canals to an area called the nasal cavity. 

Inside this area, there are millions of tiny detector cells that communicate with the brain by joining with other nerve endings. The brain processes smell in several areas, including parts of the brain that handle memories, emotions, and recognition.³ This is why smells can remind you of certain places, people, or feelings.

Anything that disrupts or hurts the process for which smell is transferred may result in anosmia.⁵

Why sense of smell matters ?

Smelling is vital for our daily lives. It alerts us in dangerous situations, detecting harmful odors like gas and smoke. It also plays a big role in enjoyable moments like savouring a meal or enjoying nature. That is why losing the ability to smell can immensely affect a person’s overall quality of life. 

Causes of chronic anosmia

A common cause of chronic anosmia is ageing. In a similar manner to hearing loss that occurs as we grow older, normal ageing is associated with decreased sensitivity to smell. As people age, they lose the number of those tiny detector cells which play a key role in detecting smell. Other than ageing, this disorder can be caused by a range of factors such as:

• Inflammatory and Obstructive Disorders: nose or sinus problems that cause swelling or block proper airflow in the nose
• Physical Trauma: injuries to the head or the face cause harm to the olfactory system, physically preventing smells travelling through the passageway 
• Congenital conditions (health problems a person is born with): like Kallmann syndrome and Turner syndrome are associated with anosmia⁵
• Infectious conditions: like Covid-19 can have long lasting symptoms, even after recovery from main infection⁶
• Other Conditions: diabetes and hypothyroidism, however it is less common. Inhaling toxic substances such as drugs, vapours and some medications can have side effects causing chronic anosmia⁵

How chronic anosmia impacts quality of life 

The inability to smell can have a severe impact on an individual's health and wellbeing. Chronic anosmia is known to affect the quality of life of individuals in some of the following ways:

Safety concerns

People with chronic anosmia often have difficulty with cooking. They tend to lose their appetite, and generally don’t enjoy eating. Research shows that they are three times more likely to face dangerous situations in the kitchen compared to people who can smell.⁷ In addition, 25 to 50 percent  of people with chronic anosmia have reported accidentally eating spoiled food.⁹

Food and nutrition

The sense of smell is influential in how we eat, helping to develop interest for food and create appetite¹ as well as tasting food.² People affected by chronic anosmia have reported experiencing a decreased enjoyment of food and drink, which often leads to less dining out at restaurants.⁸

People with chronic anosmia may also change their preferences for food, relying more on spices for example in order to enjoy food, which can at times lead to weight gain.⁴ On the other hand some people may completely lose interest in eating which may lead to unintended weight loss.⁵ 

Social and Daily Life Impact

The inability to smell unpleasant odors can affect a person’s hygiene practices.² As a result, individuals may adopt more rigorous hygiene routines such as, showering multiple times a day and increased use of deodorants, perfumes or aftershave.⁵ 

Diagnosis and medical evaluation 

You should consult your doctor if you experience noticeable changes in their ability to smell. A doctor may then ask about recent illnesses or head injuries, when the problem began, and whether there are other symptoms. The exam might include looking inside the nose with a small camera (nasal endoscopy) to check for blockages like polyps or swelling. Imaging tools like CT or MRI scans can also be used to make a diagnosis. The patient may be given smell tests to help measure how severe the problem is. Since a sudden loss of smell can be a sign of COVID-19, testing for the virus may be done.³

Treatment and coping strategies

Treatment of chronic anosmia depends on the underlying cause. If the problem is caused by something blocking the nose, like nasal polyps, treating this condition can help bring the sense of smell back. Another approach is smell training, (olfactory training) where a person practices smelling familiar scents every day to help their nose recover. Scientists are also looking into how the nerves responsible for smell can repair themselves and whether certain medicines can help with that healing.³

Living well with chronic anosmia 

If chronic anosmia is affecting how you go about your day to day life, talk to a health care practitioner. For safety reasons, people with chronic anosmia should have working fire and gas alarms in their houses and they should avoid consuming expired foods. 

FAQs

Can chronic anosmia be reversed?

In some cases if the underlying condition causing the loss of smell is treated, your sense of smell can return.

Is chronic anosmia a disability?

Yes, chronic anosmia can be considered a disability. Although it does not present like other disabilities such as blindness, chronic anosmia has the potential to pose severe safety and health risks to a person’s life.

Which types of pills can cause chronic anosmia?

Several medications may cause long term loss of smell. If you are taking medication and experiencing changes in your sense of smell don’t stop using it without talking to your doctor. Let your healthcare provider know as they may be able to adjust the medication or recommend ways to help improve your sense of smell.

Are there supplements good for the sense of smell?

Certain vitamins and nutrients play an important role in supporting a healthy sense of smell. For example, Vitamin A helps maintain the health of the nasal lining, while Vitamin B12 and zinc are essential for proper nerve function. However, while these nutrients may support olfactory function, it’s important not to self-diagnose or take supplements without medical advice. Taking high doses of certain vitamins or minerals can be harmful. Always consult with a physician before starting any supplement regimen to ensure it is safe and appropriate for your individual health needs.

Which doctor treats loss of smell?

An ear, nose and throat (ENT) specialist physician can diagnose and treat symptoms of chronic anosmia.

Summary

Chronic anosmia is not just about losing your ability to smell. It can affect how you live your day to day life and your overall good health. The way it affects a person depends on how bad the loss of smell is and how one deals with it. Our sense of smell is deeply connected to our social lives, from familiar scents like homemade meals that bring people together, to smells that bring back memories of time spent with loved ones. It's key to see how long-term loss of smell can change different parts of life’s quality. Losing your smell should not be seen just as a health problem. It also affects social life and mental health . Without proper help, those with anosmia might feel alone or cut off. Without proper help, people living with anosmia may feel lonely or isolated. That’s why health professionals should help connect patients with resources to manage these challenges. Studies have also highlighted we need more public education and further research to better tackle the problem and its effects.