Hyperosmia: When Smells Rule Your Life

The sense of smell is one of our most powerful senses: it can trigger memories, evoke a range of emotions and influence moods almost instantaneously. However, when regular odors interfere with your daily routine, you may have a condition called hyperosmia, a heightened or increased sense of smell that some people may experience on occasion or continually.

While hyperosmia is relatively rare and does not always require treatment, it has been linked to a number of medical conditions that can be more serious. So here’s what you need to know about this unusual smell disorder.

What is Hyperosmia?

People suffering from this disorder can experience strong discomfort and even illness from certain odours. Chemical smells such as synthetic fragrances, perfumes, and cleaning products are frequently reported as the cause of discomfort, although some people can be triggered by certain foods. Some conditions associated with hyperosmia can also cause a change in smell, not just an increase in sensitivity.

What causes it?

Doctors don’t usually know why someone develops hyperosmia. Because it is associated with many conditions, it can be difficult to determine whether a heightened sense of smell is a disorder in itself or a symptom of an underlying condition.

One of the most frequent causes of hyperosmia is pregnancy. One of the early symptoms of pregnancy is an increased sense of smell, which can in turn lead to headaches, nausea and vomiting during first-trimester morning sickness.

Migraine headaches can cause and be caused by hyperosmia. A recent study has shown that the disorder can happen between migraine episodes. Heightened smell sensitivity can also trigger a migraine or make you more likely to have one.

Neurological diseases such as epilepsy and multiple sclerosis, autoimmune disorders such as Addison’s disease, psychiatric conditions and Lyme disease have also been linked to hyperosmia.

Many other factors can also influence our sensitivity to smell, such as diabetes, allergies, tumors, polyps, nutritional deficiencies, some prescription medications and exposure to toxins, such as lead or mercury. 

The condition or predisposition to hyperosmia may also be genetic.

I have been particularly sensitive to smells lately. Does it mean I have hyperosmia?

This is a difficult question because so many factors can impact our sense of smell. A visit to your ENT Specialist is recommended if your increased sensitivity to smells is persistent and if you feel that there has been a change in the way you perceive odors.

How is it diagnosed?

On your visit, your doctor will likely want to rule out any physical causes for the smelling issue, such as tumors or polyps. A nasal endoscopy may be performed in this case. If everything looks good, a smell test may also be conducted. If results show an increased sense of smell, hyperosmia is usually the diagnosis. Imaging tests can also be useful in pinpointing underlying issues.

Are there treatments for hyperosmia?

Beyond that, treatment of hyperosmia involves finding and treating the underlying cause of the symptom. For example, people with hyperosmia due to disorders impacting the nervous system may benefit from taking medications for their condition. Or if you’ve experienced hyperosmia after starting a new prescription, you may want to ask your doctor about changing medications.

That said, identifying the right treatment can be challenging since causes are difficult to find. In such cases, managing symptoms may be the best approach until the cause is determined. For instance, isotonic nasal wash will usually be helpful to wash away any irritants/mucous. Peppermint gum or candy can cover off-putting odors. Some medications can also help with any nausea caused by the hypersensitivity to smells. Or you may need to wear a mask if you work in an environment with strong odors.

Finally, avoiding specific triggers when possible is also beneficial once you have identified what they are. Triggers vary by individual: Some people can’t tolerate scented candles, others experience discomfort from certain foods.

All in all, while hyperosmia can cause discomfort, it is rarely a major problem. At times, it can even be life saving in detecting dangerous situations, such as a fire, gas leak, or spoiled food. Nevertheless, if hyperosmia is interfering with your everyday life, consult your doctor so that aromas don’t prevent you from being around other people and enjoy life!

Dr. David Ho 何志謙醫生 graduated from the University of Melbourne Medical School and obtained Otorhinolaryngology (Ear, Nose & Throat) Specialist training under the Royal Australasian College of Surgeons. Before returning to Hong Kong, he worked at Royal Children’s Hospitals in Melbourne, the biggest pediatric medical centre in the Southern Hemisphere and was a specialist ENT consultant at Royal Melbourne, Alfred and Austin Hospitals. He obtained post-fellowship training in New York, Hong Kong and London, Canada. He is now an honorary assistant professor at the University of Hong Kong and an honorary Specialist ENT Consultant for the Matilda International Hospital. His private practice is in Room 707, Central Building, Central: The Hong Kong ENT & Sleep Surgery Centre.