Hyperosmia: Definition and Causes

Smell is an essential sense that allows us to access a large number of odors, both pleasant and unpleasant. Likewise, there are different conditions that can interfere with this sense. Read on to find out what hyperosmia is and its various causes!
Hyperosmia: Definition and Causes
Sara Clemente

Written and verified by psychologist and journalist Sara Clemente.

Last update: 05 June, 2023

People with hyperosmia can, for example, detect the scent of a flower even in a pile of trash. They can also recognize the smell of a person from far away. That doesn’t mean they suddenly become bloodhounds or have superhuman abilities. It just means they’ve developed a hypersensitivity specific to their sense of smell.

Hyperosmia: quality or disorder?

This sharp sense of smell has as many advantages as it does unpleasant consequences for everyone who has it. Some people see it as an overall blessing in their lives, but other people see it as a source of endless suffering. Let’s look at some examples. 

smelling flower

If you’re at the foot of the stairs in your apartment building and you get a whiff of the wonderful stew or the cake one of your neighbors is making, you’ll usually get a huge appetite. You’re so hungry!

You want to scarf that food down so badly! And if you have food close by or if you know your neighbor, it’s a great thing. But if what you smell so intensely and constantly isn’t very appetizing or if you can’t do anything about the need you suddenly feel (hunger), things are different. 

Now, while you’re calmly resting in your living room after a long day at work, you start to smell all kinds of things without any way of avoiding them.

The shoe polishes your neighbor on the first floor uses, a bathroom air freshener, some lacquer from the lady on the fifth floor, or the oil from a burnt pot. It’s like that every day, all the time.

The only thing any of that would make you want to do is spend all your time with a clothespin on your nose. 

What causes hyperosmia?

This illness shows up in the same area, although on the opposite side, as two other kinds of perceptual disorders related to smell. The first one is hyposmia, a reduced sense of smell, and the second one is anosmia, a total lack of any sense of smell.

Out of these three, hyperosmia is the least common. What that means is that it hasn’t been studied much. It’s the very fact that it doesn’t happen to many people that’s made it so we aren’t very sure about what causes it.

On the other hand, we do know about specific causes or risk factors related to things like menopause, Addison’s disease, hyperthyroidism, or the neural damage caused by taking amphetamines or going through withdrawal.

In some cases, hyperosmia ends up going away on its own. It shows up for a specific amount of time and disappears. There are only some extreme cases where it lasts a person’s whole life.

Is it helpful or harmful?

For a perfumer or a sommelier, having hyperosmia would be a huge advantage. This is what happens with the main character in the book and the movie with the same name, Perfume: The Story of a MurdererHis hypersensitive smell helps him become one of the best at his job. But for everyone else it can turn into pure torture.

smelling wine

This disorder causes very serious problems in social settings. This is because of the unpleasantness or disgust they might start to feel about some things.

For example, they could start to see their favorite food as gross or their preferred perfume as unbearable. They might even end up fainting if they get stuck in very crowded spaces or huge groups of people, like on the subway or the bus.

What makes hyperosmia go away?

Because we aren’t sure about what causes it, our treatments and ways to deal with hyperosmia have conflicting results. For example, doctors have tried using antipsychotic dopamine antagonist substances to treat the disorder. 

By inhibiting those neurotransmitters they’re able to limit the amount of smells that make it to your olfactory bulb.

Thanks to testimonials from people who have it, we know that smoking is also a way to reduce your sense of smell if you have hyperosmia. But be careful!

You have to take that with a grain of salt, because if there’s one thing that really does have plenty of scientific evidence it’s that smoking isn’t good for your health at all.

That’s why the first thing people with it and anyone around those people should definitely do is avoid or remove any strong smells that might be truly impossible for those people to handle. 

These are things like fish, meat, certain sauces, or coffee. Since there’s no medical treatment the only thing these people can do is try to limit their exposure.

Pregnant women and hyperosmia

One strange thing is that a lot of the women who go through this kind of “temporary” disorder are pregnant. So during the beginning and end of their pregnancy, they’ll have a hypersensitive sense of smell, mainly because there’s a higher concentration of estrogen and progesterone in their blood.

These women have a sharper sense of smell. They might start to dislike smells they used to like, and vice versa. It can even make them vomit more often when they pick up on truly disgusting smells.

For some pregnant women, this change fades away or disappears after the first trimester. But for other women it stays around the whole time they’re pregnant and goes away gradually after they give birth.

pregnant lady

This physiological change might be something we got from our ancestors so that mothers can recognize the smell of their baby when it’s born. 

Dysosmia is a neurological disorder that causes a change in your sense of smell. It can show up as anosmia (we mentioned this earlier), parosmia, or phantosmia.

  • Parosmia has to do with a deterioration in your sense of smell, which makes it so your brain can’t correctly pick out something’s natural or inherent smell. For example, someone might find the smell of a rose unpleasant, even though it’s usually pleasant.
  • Phantosmia is a kind of smell hallucination. This means someone with it might pick up on smells that don’t exist or aren’t actually there. That ghost odor makes people think they smell natural gas, or some kind of leak, so they think they’re in a dangerous situation. They really get a strong feeling they’re smelling it.

The smell of something fried, no matter how fatty it is, won’t satisfy your appetite by itself. We need to do more research about these kinds of disorders, especially hyperosmia. We have to know why and how it shows up to be able to reduce its effect on the lives of the people who have it.

All cited sources were thoroughly reviewed by our team to ensure their quality, reliability, currency, and validity. The bibliography of this article was considered reliable and of academic or scientific accuracy.

  • Delegido, C., & José, M. (2016). Revisión bibliográfica de los diferentes tipos de tratamientos en el abordaje de los trastornos olfativos.
  • Piñol, L. S., Ortego, J. G., & Vilar, P. B. (2015). Parosmia como debut de una Displasia Fibrosa. Acta Otorrinolaringológica Gallega, (8), 1-8.
  • Ropper, A., & Brown, R. (2007). Trastornos del olfato y el gusto. Principios de Neurología, 195-202.

This text is provided for informational purposes only and does not replace consultation with a professional. If in doubt, consult your specialist.