Changes in your sense of smell

What is a change in your sense of smell?

A change in your sense of smell means the way you smell things is different from what's normal for you. You might notice smells less strongly, not at all, or find that familiar things suddenly smell wrong, unpleasant, or like something that isn't really there.

What causes a change in your sense of smell?

Smell changes usually happen when something stops smells reaching the nerve endings inside the top of your nose, or when those nerve endings are themselves irritated or damaged. Because so many different things can cause this, a change in smell is rarely a condition on its own; it's usually a sign of something else going on.

Common causes include:

• a cold, flu, or COVID-19 infection
• sinusitis (a sinus infection)
• an allergy such as hay fever
• growths inside your nose (nasal polyps)
• smoking
• certain medicines, including some antibiotics, antihistamines, and medicines for cholesterol or blood pressure
• a knock or injury to your head
• radiotherapy or chemotherapy, or certain cancers affecting the head and neck
• getting older, which naturally reduces your sense of smell over time.

Less often, a change in smell is linked to a nervous system condition such as Parkinson's disease, or to a growth or injury affecting the smell nerves themselves.

Are there different types of smell change?

Yes. Doctors describe four main types of smell change:

• Hyposmia: Reduced sense of smell
• Anosmia: Total loss of smell, which is rare from birth but more often develops later in life
• Parosmia: A distorted sense of smell, where familiar things, such as coffee or cooked food, suddenly smell wrong or unpleasant
• Phantosmia: Smelling something that isn't there, such as smoke, burning, or chemicals, when nothing is actually there.

Your sense of smell is closely linked to taste, so many people with a smell change also notice changes in how food tastes.

How is a change in smell diagnosed?

If you see a doctor about a change in your smell, they'll usually ask about your health history, including any recent infections, injuries or illnesses, and examine your nose, ears and throat. They may also ask about the medicines you're taking, since some can affect your sense of smell.

If there's no obvious cause, you may be referred to a specialist for further tests.

How is a change in smell treated?

Treatment usually focuses on the underlying cause. This might mean antibiotics for a sinus infection, steroid nasal sprays or drops for sinusitis or nasal polyps (which help around 10 to 25% of people with a post-viral smell change), surgery to remove polyps, or a change in medicine if a drug you're taking is responsible.

A treatment called smell training may also help. This involves deliberately sniffing a set of strong scents, such as citrus, cloves or eucalyptus, every day while concentrating on what they should smell like; it can take around 6 to 12 weeks to notice a difference, and up to 24 weeks for the full effect.

If cooking and eating are harder because of a changed sense of smell, it may help to:

• stick to foods that are cold or at room temperature, rather than hot food that releases more aroma
• use a kitchen fan or open a window while cooking
• keep opened food covered, and use a lidded cup and a straw for drinks
• keep a diary of the smells that trigger problems, so you can spot patterns and things to avoid.

When should I see a doctor?

See a doctor if your sense of smell hasn't gone back to normal after a week or two, though it's reasonable to allow a few weeks if it's gradually improving. It's also worth getting it checked because smell changes can occasionally point to another health condition, and because a lasting change can affect your mood and wellbeing.

Get it checked especially if:

• you're going through cancer treatment and notice any change in your smell
• the change in smell is affecting your mood, appetite or weight
• you can't smell hazards such as smoke or gas, so you need to rely on other safety measures instead.