When the World Loses Its Smell: An Overlooked Side of Parkinson’s
Imagine walking past a bakery.
Fresh bread is coming out of the oven.
People around you can smell it before they even reach the door.
But you can’t.
Or perhaps somebody makes your favourite coffee.
You recognise the taste. You enjoy the warmth. You know exactly what you’re drinking.
But that familiar aroma is missing.
Maybe you’ve noticed it gradually.
Or perhaps you haven’t noticed it at all.
For some people living with Parkinson’s, this is an everyday reality.
Changes to the sense of smell are among the lesser-known non-motor symptoms of Parkinson’s, and they can begin long before the condition is diagnosed.
Parkinson’s Is About More Than Movement
When most people think of Parkinson’s, they think of tremor, stiffness or slower movement.
These are among the most recognisable symptoms.
But Parkinson’s can affect much more than the body’s ability to move.
Sleep, digestion, mood, thinking and other functions may also be affected.
One of the less obvious changes involves our sense of smell.
The medical term for a reduced ability to smell is hyposmia.
A complete loss of smell is called anosmia.
Both can occur for many reasons, but reduced smell is particularly relevant to Parkinson’s because it can develop during the early stages of the disease process.
It Can Begin Years Before Diagnosis
One of the most interesting aspects of smell changes in Parkinson’s is their timing.
For some people, reduced smell develops years before noticeable movement difficulties.
That means somebody may experience the symptom without having any reason to connect it to a neurological condition.
They may simply assume their sense of smell isn’t as good as it used to be.
Perhaps they blame ageing.
Perhaps they remember having a particularly bad cold.
Or perhaps they don’t notice the change because it happens gradually.
It may only become significant much later, when a Parkinson’s diagnosis prompts them to think back over earlier changes.
Some people then realise that familiar smells had been fading for years.
Why Can Parkinson’s Affect Smell?
Our sense of smell involves specialised sensory cells in the nose and complex pathways in the brain.
These systems allow us to detect odours and recognise what they mean.
Parkinson’s involves changes in several brain systems, not only those responsible for movement.
Research has identified abnormalities in areas associated with smell processing, including the olfactory bulb and related brain regions.
Scientists continue to investigate exactly how these changes develop and how they relate to the wider progression of Parkinson’s.
The important point is that Parkinson’s can affect neurological functions well beyond movement.
Smell changes are one example of why Parkinson’s should never be understood as simply a condition that causes shaking.
Not Everyone Notices Their Sense of Smell Changing
Smell is an unusual sense because we don’t always consciously monitor it.
We notice a strong perfume.
Freshly cut grass.
Food cooking.
Smoke.
But we don’t normally stop to check whether our sense of smell is working correctly.
And when it declines gradually, our brain may simply adapt to receiving less information.
Someone might still enjoy their meals.
They might still recognise familiar surroundings.
They may not realise that other people are experiencing smells they can no longer detect.
This is one reason smell changes can go unrecognised.
The Connection Between Smell and Taste
People often say that food has lost its taste when their sense of smell changes.
But taste and smell are different senses that work closely together.
Our tongue detects basic tastes such as sweet, salty, sour, bitter and umami.
Much of what we experience as the flavour of food also comes from aroma.
When we chew, aromatic compounds travel towards the smell receptors through the back of the nose.
This process contributes significantly to the experience of flavour.
So someone with reduced smell may still recognise that something is sweet or salty but find that the overall flavour is less distinctive.
A favourite meal may seem less satisfying.
Different foods may begin to taste more similar.
And certain aromas that once made a meal appealing may no longer be noticeable.
Why Food May Become Less Enjoyable
Imagine a Sunday roast.
Part of the enjoyment begins long before the food reaches the table.
The smell of roasting potatoes.
Vegetables cooking.
Gravy being prepared.
Those aromas build anticipation.
They become part of the experience.
If somebody cannot smell them, something familiar may be missing.
That doesn’t mean the person cannot enjoy food.
Texture, temperature, presentation and basic tastes still contribute to eating.
But the experience may be different.
For some people, reduced smell can contribute to changes in appetite or enjoyment of meals.
Because maintaining good nutrition is important, persistent changes in appetite or unintentional weight loss should be discussed with an appropriate healthcare professional.
Smell Is Closely Connected to Memory
There’s another reason smell matters.
It can bring back memories with remarkable intensity.
A particular perfume might remind you of a parent or grandparent.
The smell of the sea may bring back childhood holidays.
Freshly cut grass might remind you of summer afternoons.
A certain meal may transport you straight back to a family kitchen.
Smell has close connections with brain systems involved in emotion and memory.
That’s why a familiar aroma can sometimes trigger such a powerful personal response.
When the ability to detect smells diminishes, some of those everyday sensory experiences may become less accessible.
It isn’t necessarily something other people will notice.
But it can still represent a meaningful change.
There’s Also a Practical Safety Issue
Our sense of smell does more than make life enjoyable.
It also helps warn us about certain dangers.
Smoke.
Gas leaks where an odourant has been added.
Some forms of spoiled food.
Chemical fumes.
Someone with reduced smell may not notice these warning signs as readily as another person.
That makes practical precautions particularly important.
Working smoke alarms should be installed and maintained in accordance with local fire safety guidance.
Where gas is used, an appropriate gas detector may provide additional protection, alongside properly maintained appliances.
Food safety should be based on storage instructions, use-by dates and safe handling rather than relying on smell alone.
Even people with a normal sense of smell cannot reliably detect every dangerous gas or identify every unsafe food by its odour.
These precautions are sensible for everyone, but they can be especially valuable when smell is reduced.
Can You Have Loss of Smell Without Parkinson’s?
Absolutely.
And this is an important distinction.
Reduced smell is not unique to Parkinson’s.
It can occur with:
- Respiratory infections, including COVID-19.
- Sinus problems and nasal polyps.
- Allergies and nasal inflammation.
- Head injuries.
- Some medications.
- Age-related changes.
- Other neurological conditions.
Many people experience changes in smell without ever developing Parkinson’s.
Loss of smell alone does not mean somebody has Parkinson’s.
It is one piece of information that may become relevant when considered alongside other symptoms and clinical findings.
If smell changes are persistent, unexplained or concerning, a GP can assess possible causes and determine whether further investigation is appropriate.
Could Smell Testing Help Detect Parkinson’s Earlier?
Researchers are interested in smell testing because reduced smell can occur before the movement symptoms associated with Parkinson’s.
Standardised smell identification tests can help assess how well someone recognises particular odours.
In research, smell testing may be considered alongside other information, including certain sleep symptoms, clinical assessments and biological markers.
However, smell testing cannot independently diagnose Parkinson’s.
Many people without Parkinson’s have a reduced sense of smell, while not everyone with Parkinson’s experiences the symptom.
There is currently no single smell test that can reliably tell an individual whether they have or will develop Parkinson’s.
Research into earlier detection continues because recognising the disease process before significant movement symptoms develop could be important for future treatments and clinical trials.
Can Smell Return?
That depends on the cause.
When smell changes result from some infections or nasal conditions, improvement may be possible.
For Parkinson’s-related smell loss, there is currently no established treatment that reliably restores normal smell.
Parkinson’s medications used to manage movement symptoms do not consistently reverse this particular difficulty.
Smell training, which involves regularly smelling selected odours, is used for some forms of smell loss, particularly following infections. Its effectiveness specifically for Parkinson’s-related smell impairment remains uncertain.
Anyone considering treatment for persistent smell changes should seek appropriate medical advice to establish the likely cause and discuss suitable options.
Finding Other Ways to Enjoy Food
If reduced smell is affecting the enjoyment of meals, some practical adjustments may help.
Different textures can make food more interesting.
Colourful presentation may improve its appeal.
Temperature contrasts can contribute to the eating experience.
Herbs, seasonings and varied ingredients may help some people enjoy meals more, although preferences differ.
It is important not to compensate automatically by adding excessive salt or sugar, particularly where other health conditions require dietary management.
If eating becomes difficult or appetite changes significantly, a dietitian or Parkinson’s healthcare professional may be able to offer individual advice.
The objective isn’t to make every meal complicated.
It’s to find ways of keeping food enjoyable and nutritionally appropriate.
The Symptoms Other People Cannot See
One of the difficulties with non-motor symptoms is that they are often invisible.
Someone can lose much of their sense of smell without anyone around them noticing.
There may be no obvious outward sign.
They may continue working, socialising and going about everyday life.
Yet their sensory experience of the world has changed.
This is a useful reminder that Parkinson’s is much broader than its most recognisable physical symptoms.
Two people with the same diagnosis can have very different experiences.
And someone who appears to have relatively mild movement difficulties may still be managing non-motor symptoms that affect their daily life.
Why Awareness Matters
We tend to associate Parkinson’s with the things we can see.
A tremor.
A change in walking.
Slower movement.
Difficulty getting out of a chair.
But the condition can also affect experiences that are much harder to observe.
The aroma of a morning coffee.
The smell of flowers in the garden.
The familiar scent of a family home.
The warning smell of something burning.
These may seem like small details.
But together, our senses help shape how we experience the world.
Understanding smell changes helps us recognise another dimension of living with Parkinson’s.
Sometimes It’s What You Don’t Notice
Perhaps the most unusual thing about losing your sense of smell is that it may happen without a dramatic moment.
There may be no sudden realisation.
No obvious event.
No particular day when everything changes.
Instead, familiar smells gradually become less noticeable.
And because the change is so subtle, it may take years before someone connects it with anything significant.
That is one reason awareness of non-motor symptoms matters.
Not because every change should cause alarm.
And not because loss of smell automatically indicates Parkinson’s.
But because understanding the full range of symptoms helps us see the condition more accurately.
Parkinson’s doesn’t only change how some people move through the world. It can change how they experience the world itself.
Join Us at Hullbridge Parkinson’s Cafe
At Hullbridge Parkinson’s Cafe, we believe that understanding Parkinson’s means recognising both the visible and invisible aspects of the condition.
Our friendly community welcomes people living with Parkinson’s, their partners, families and carers.
We meet at Hullbridge Free Church, 47–48 Lower Road, Hullbridge, Essex SS5 6DF, on the first and third Tuesday of each month, from 11:00am to 1:00pm.
No booking is required. New faces are always welcome.
Find out more at https://parkinsonscafe.co.uk/.
This article is for general information and does not replace professional medical advice. Persistent or unexplained changes in smell should be discussed with an appropriate healthcare professional.
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