Anosmia: Loss of Smell – Causes, Symptoms, Diagnosis, and Treatment
Anosmia, or the loss of smell, can impact taste, safety, and overall well-being. Discover its causes, symptoms, diagnosis, and treatment options to manage and restore your sense of smell effectively.
Written by Dr.Sonia Bhatt
Last updated on 3rd Jul, 2025
Introduction
Our sense of smell plays a big role in our daily lives, from how we enjoy food to how we stay safe by detecting things like smoke or gas. Imagine what it would be like to live without that sense – that’s what happens with a condition called anosmia. Anosmia is the complete loss of the sense of smell, and it can really affect a person’s quality of life. In this article, we’ll dive into what causes anosmia, how to recognise its symptoms, how it’s diagnosed, and the different treatment options available.
What is Anosmia?
Anosmia is defined as the loss of the ability to detect odours. While some people may experience partial loss of smell, known as hyposmia, anosmia refers to the total inability to perceive any scents. This condition can be temporary or permanent, depending on its underlying cause. The olfactory system, responsible for detecting smells, plays a vital role in our sensory experience, including taste. When anosmia occurs, it may affect a person’s ability to enjoy food and beverages and even lead to dangerous situations when smells like smoke or spoiled food go undetected.
Causes of Anosmia
The causes of anosmia vary greatly, ranging from common, treatable conditions to more complex health issues. Let’s take a closer look at some of the most common reasons behind the loss of smell:
Nasal Congestion and Infections: Common colds, flu, and sinus infections can cause temporary anosmia by blocking the nasal passages and preventing odour molecules from reaching the olfactory receptors. Chronic sinusitis and allergic rhinitis are also common culprits.
Nasal Polyps and Blockages: Nasal polyps, which are non-cancerous growths in the nasal passages, can obstruct the airflow and lead to anosmia. Other structural abnormalities, such as a deviated septum, can also contribute to the loss of smell.
Traumatic Brain Injury and Nerve Damage: Head injuries can damage the olfactory nerves or the olfactory bulb, leading to anosmia. This type of anosmia can be permanent if the damage is severe.
Exposure to Toxic Chemicals: Certain chemicals, such as pesticides, solvents, and heavy metals, can damage the olfactory receptors and result in anosmia. Occupational exposure to these substances is a known risk factor.
Medications: Some medications, including certain antibiotics, antihistamines, and chemotherapy drugs, can cause anosmia as a side effect. The loss of smell usually resolves once the medication is discontinued.
Ageing: As people age, their sense of smell naturally declines. Anosmia is more common in individuals over the age of 60 due to the natural degeneration of olfactory receptors.
Medical Conditions: Anosmia can be a symptom of underlying medical conditions such as Alzheimer's disease, Parkinson's disease, multiple sclerosis, and chronic kidney disease. These conditions can affect the nervous system and disrupt the sense of smell.
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Symptoms of Anosmia
The primary symptom of anosmia is, of course, the loss of the sense of smell. However, there are additional symptoms that can accompany this condition, depending on its underlying cause:
Complete loss of smell: The inability to detect any odours at all.
Partial loss of smell (hyposmia): A reduced ability to detect odours or a diminished sensitivity to smells.
Changes in taste: Since smell and taste are closely linked, anosmia often affects the sense of taste. Foods may seem bland or tasteless, which can lead to poor appetite and nutritional concerns.
Loss of flavour: Without the ability to smell, foods may taste different, and the enjoyment of meals can be severely diminished.
Social and emotional effects: Anosmia can cause frustration, anxiety, and a sense of isolation. People with anosmia may also be at a higher risk of safety concerns, such as being unaware of gas leaks, smoke, or spoiled food.
Diagnosing Anosmia
A thorough diagnosis is essential to determine the underlying cause of anosmia. A healthcare professional, typically an otolaryngologist (ENT specialist), will assess the patient’s medical history and conduct a physical examination. In some cases, additional tests may be needed, such as:
Smell tests: Various smell identification tests can be used to assess the degree of smell loss and identify which odours the person can or cannot detect.
Imaging studies: CT scans or MRIs may be used to identify structural abnormalities in the nasal passages, sinuses, or brain that could be contributing to anosmia.
Blood tests: These can be used to check for underlying conditions, such as nutritional deficiencies or thyroid issues.
Early diagnosis is important because treating the underlying cause can help restore the sense of smell in some cases, especially if the anosmia is due to a reversible condition such as a sinus infection or viral illness.
Treatment Options for Anosmia
Treatment for anosmia largely depends on the cause. Here are some common approaches:
1. Treating Underlying Conditions
Addressing the root cause of anosmia is often the key to restoring the sense of smell.
Infections: If anosmia is caused by a cold, flu, or sinus infection, treating the infection can help restore the sense of smell. This may involve using decongestants, antihistamines, or antibiotics.
Nasal Polyps: Surgical removal of nasal polyps can improve airflow and restore the sense of smell.
Structural Abnormalities: Correcting structural issues, such as a deviated septum, through surgery can help alleviate anosmia.
2. Medications
Certain medications can help reduce inflammation, fight infections, or manage allergies that contribute to anosmia.
Corticosteroids: Oral or nasal corticosteroids can reduce inflammation in the nasal passages and improve the sense of smell, especially in cases of chronic sinusitis or nasal polyps.
Antibiotics: If a bacterial infection is causing anosmia, antibiotics may be prescribed to treat the infection.
Antihistamines: For anosmia caused by allergies, antihistamines can help reduce symptoms and restore the sense of smell.
3. Smell Training
Smell training is a simple but effective therapy that involves sniffing different scents regularly to help "retrain" your nose and brain. By exposing yourself to various smells—like lemon, rose, or cloves—your brain starts to reconnect with your sense of smell, even if it's been lost. This technique has been especially helpful for people who lose their sense of smell after a viral infection, like a cold or COVID-19. It may take some time, but many people find that practising smell training can help them regain their sense of smell gradually.
4. Supportive Therapies
Some people find acupuncture, which involves tiny needles placed at specific points on the body, helpful for improving their sense of smell. However, it’s important to note that it doesn’t work for everyone. Additionally, certain nutritional supplements like zinc and vitamin A can play a role in supporting olfactory function. While these supplements might not fully restore the sense of smell, they may help improve it a little or prevent further decline. If you’re considering trying supplements, it’s always a good idea to talk to your doctor first to make sure they’re safe and suitable for your needs.
Conclusion
Anosmia, the loss of the sense of smell, can significantly affect a person's life in many ways. It might seem like a small issue, but the absence of smell can make everyday experiences more challenging, from enjoying your favourite foods to recognising dangerous situations like gas leaks or smoke. Anosmia can be caused by many different factors, such as infections, nasal blockages, head injuries, or neurological conditions, and the treatment options depend on what's causing it. Whether the loss of smell is temporary or permanent, it can deeply influence a person’s quality of life, impacting not just physical health but also emotional well-being. If you or someone you know is dealing with anosmia, it's important to seek medical advice to figure out the cause and find the right course of action for treatment.
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Consult Top ENT Specialists
Dr. Riya Das
Ent Specialist
8 Years • MBBS, MS ENT(oto rhino laryngology)
East Midnapore
VIVEKANANDA SEBA SADAN, East Midnapore
Dr Vaishnavi Shetty
Ent Specialist
5 Years • M. B. B. S , M.S.Otorhinolaryngology
Bengaluru
Apollo Medical Center, Marathahalli, Bengaluru
Dr. Mayur Nair
Ent Specialist
11 Years • MBBS, MS - ENT
Bengaluru
Apollo Clinic, Sarjapur Road, Bengaluru
Dr. Shalu Sharma
Ent Specialist
14 Years • MBBS, DLO, DNB (ENT)
Delhi
Salus Advanced ENT Care, Delhi
Dr. Prof. Suresh Singh Naruka
Ent Specialist
16 Years • MBBS (Medicine),MS (ENT, Otorhinolaryngology, and Head & Neck Surgery)
Delhi
Apollo Hospitals Indraprastha, Delhi
(900+ Patients)
