Bad Smell in Nose: Related Conditions, Outlook, and More

Medically Reviewed By Alana Biggers, M.D., MPH
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Many causes of a bad smell in the nose, such as the common cold, are easily treatable. However, others may need medical attention, such as digestive conditions and kidney and liver diseases. Sometimes a bad smell can come from your environment. However, if the smell does not go away or continues despite changing your surroundings, it may indicate an underlying health condition.

Read on to learn why you may experience a bad smell in your nose and the treatments. This article also details when to seek medical care.

Food and drinks

A closeup of a person's nose
Yana Bulgakova/Stocksy United

The ability to smell can enhance the enjoyment of food and how it tastes. However, some foods and drinks may cause a lingering, unpleasant aftertaste or bad smell in the nose. These may include:

  • garlic
  • onions
  • certain spices
  • alcoholic beverages
  • coffee

Treatment

If you notice an unpleasant smell after eating a certain food, consider limiting the food in your diet. If the unpleasant odor continues, contact a doctor for further advice.

Dental conditions and improper hygiene

Tooth decay, also known as dental caries, is when bacteria that induce decay cause your mouth to become acidic. The acid can break down the teeth’s surfaces and may lead to cavities. 

Cavities can trap food and bacteria, causing unpleasant smells. These smells may travel up through the back of your throat and into your sinuses, causing a bad smell in your nose. 

Periodontal disease, or gum disease, may also cause an unpleasant smell. It occurs when plaque — a thin, sticky layer of bacteria — builds up on the teeth and hardens.

Without treatment, tooth and gum conditions may lead to pain and loss of teeth. 

Treatment

Contact a dentist if you suspect you have a condition affecting your tooth or gum health. Fillings or fluoride treatments may help.

Proper hygiene of the teeth and gums is also important to treat and prevent infections and decay. This can include brushing your teeth twice daily and flossing regularly.

Phantosmia and parosmia

Phantosmia describes the sensation of smelling something that is not there. Parosmia refers to when you perceive real scents differently, such as smelling foulness when smelling food.

Parosmia and phantosmia may cause you to detect a bad smell.

They are both olfactory (smell) dysfunctions that occur due to impairments in how the nose perceives smells or how the brain processes them. For example, causes of smell disorders include:

  • respiratory infections
  • head injury
  • exposure to certain chemicals may cause smells disorders

COVID-19 is commonly associated with a loss of smell, or anosmia. However, clinicians, including researchers from a 2021 case study, have reported several cases of phantosmia during and after a COVID-19 infection.

Treatment

Some people’s typical sense of smell recovers over time. Others may continue to experience symptoms. Treatment can include addressing the underlying cause and training to recover your sense of smell.

Learn more about the causes and treatment of parosmia and phantosmia.

Postnasal drip

A postnasal drip is when mucus thickens or builds up and may drip down the throat. This can occur as a result of infection or irritation, for example, due to:

  • common cold
  • flu
  • other infection
  • other nasal conditions, such as sinusitis or nasal polyps
  • allergies
  • asthma
  • irritating chemicals
  • cold air

Sometimes, a postnasal drip can produce bad-smelling mucus. Mucus may trap bacteria, allowing them to grow. As the nose, throat, and other airways are connected, your nose may detect these smells.

Treatment

Treatment for postnasal drip will depend on its cause. Options may include medication to resolve an infection or allergic response, over-the-counter (OTC), or home care, such as nasal sprays and decongestants.

Learn more about postnasal drip, including its causes and treatment.

Sinusitis

Sinusitis is a common condition that refers to the inflammation of the sinuses. It is often caused by infection from a virus, bacteria, or fungus. The inflammation may cause the sinuses to produce a bad-smelling mucus or postnasal drip.

Treatment

Sinusitis typically goes away in 2–3 weeks.

In the meantime, at-home care methods such as a nasal rinse or decongestant may help alleviate symptoms. In some cases, bacterial sinusitis may require antibiotics.

Nasal polyps 

Nasal polyps are small, noncancerous soft tissue growths of the nose or sinus cavities. They may occur due to conditions that cause inflammation, such as rhinosinusitis or allergies.

Smaller nasal polyps may not cause any obvious symptoms. However, large nasal polyps can block airways and cause further problems such as:

The buildup of congestion and the possible sinus infection may also cause a postnasal drip, leading to a bad nose smell. Nasal polyps may also cause parosmia.

Treatment

Nasal polyps can sometimes shrink with steroid sprays or allergy medication. Large polyps may require surgical removal.  

Smoking and tobacco use

Tobacco products can weaken your teeth and gums, leading to tooth or gum conditions that cause an odor. Tobacco products may include:

  • cigarettes
  • pipes
  • cigars
  • e-cigarettes
  • chewing tobacco

Treatment

Tobacco may also lead to halitosis (bad breath) or an unpleasant smell in the nose and mouth due to it decreasing the amount of saliva in your mouth. Saliva helps keep the mouth clean. Low amounts of saliva can lead to halitosis.

Other causes 

Several other causes may lead to bad smells in the nose, including:

  • Digestive conditions: Conditions such as acid reflux and gastroesophageal reflux disease (GERD) can cause an unpleasant taste or smell in the airways.
  • Tonsil stones: These are hard and sometimes painful particles of bacteria and debris that get stuck in the crevices of your tonsils, causing an unpleasant odor. 
  • Kidney disease: Kidney disease can sometimes cause ammonia-like odors from the breath, as the kidneys may not be able to excrete the ammonia that the body produces.
  • Liver disease: Severe liver disease may cause people to experience a strong, unpleasant odor on their breath.
  • Certain medications: Certain medications may lead to smell disorders, such as phantosmia or parosmia. These medications can include some antibiotics and antihistamines.
  • Foreign bodies: A foreign body stuck in the nose may cause a bad smell as it starts to accumulate bacteria.

When to seek medical help

While some cases of a bad smell in the nose can be mild, such as a common cold, some cases may need medical treatment.

Contact your doctor if:

  • the smell may be coming from an unpleasant-smelling mucus
  • you experience other symptoms of illness, such as:
    • head or facial pain or pressure
    • fever
    • tooth or gum pain
    • persistent cough
    • symptoms in other areas of the body, for example, stomach pain
  • the smell worsens, does not improve, or improves and then returns

Your doctor or dentist will ask about your symptoms and medical history. They will examine your sinuses and the back of your throat. Also, they may refer you to an ear, nose, and throat specialist called an “ENT” doctor. 

How to get rid of bad smells in your nose naturally

Treatment involves focusing on the underlying condition. Natural methods will not cure some conditions, such as large nasal polyps.

However, some home care methods may support your healthcare professional’s treatment plan, including:

  • proper oral hygiene by brushing your teeth twice a day and flossing regularly
  • saline sprays or mists
  • humidifiers
  • adequate hydration
  • avoiding known triggers of your symptoms, such as tobacco

If home care steps do not work, contact your doctor.

Summary

Many conditions that cause bacteria to build in the mouth or airways can result in a bad smell in the nose. This includes sinusitis, postnasal drip, and tooth decay. Other causes include certain foods or medications, olfactory disorders, and kidney disease.

Some of these causes may not require intensive medical treatment. Others may need treatment by a doctor. Often, treatment that improves the underlying cause can help improve the unpleasant odor in the nose.

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Medical Reviewer: Alana Biggers, M.D., MPH
Last Review Date: 2022 Oct 27
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THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. Never ignore professional medical advice in seeking treatment because of something you have read on the site. If you think you may have a medical emergency, immediately call your doctor or dial 911.
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