why do sneezes smell bad illustration

The 7+ Reasons Why Your Sneezes Smell (2024)

by | Updated: Mar 20, 2024

The act of sneezing, while commonplace, often raises a peculiar question:

Why do some sneezes produce a distinctive odor?

Delving into the intricacies of the human nasal passages, the environment they provide, and the elements they expel, provides insight into the aromatic aspect of a sneeze.

Why Do Sneezes Smell?

Sneezes can sometimes have a noticeable smell due to the expulsion of bacteria and particles from the nasal passages. The moist environment of the nose is a breeding ground for bacteria. When sneezing, a mix of mucus, bacteria, and breath is released. The odor can be more pronounced if there are infections, dietary factors, or dental issues present.

Person sneezing with a bad smell vector illustration

Types of Sneeze Odors

The act of sneezing can sometimes be associated with various odors, which can be influenced by a range of factors.

Here are some types of sneeze odors and their possible causes:

  • Musty or Moldy: Can be caused by the presence of fungi or mold spores in the nasal passages or sinus cavities.
  • Sweet: Certain bacterial infections, especially Pseudomonas aeruginosa, can produce a sweet or fruity odor.
  • Foul or Rotten: Sinus infections or the presence of trapped old mucus can lead to this smell. It can also arise from poor dental hygiene or tonsillitis.
  • Metallic: Sometimes, tiny amounts of blood in the nasal passages or sinus cavities can give a metallic odor to the sneeze.
  • Sulfuric or Rotten Egg: Some bacteria produce hydrogen sulfide gas, which can lend this specific smell. It can also be influenced by certain foods consumed, like those high in sulfur.
  • Medicinal or Chemical: The use of nasal sprays or other medications can sometimes cause a sneeze to have this odor.
  • Neutral or No Odor: Many sneezes might not have any discernible odor at all, especially when the nasal passages are clear, and there are no underlying infections or irritations.

Note: Not everyone may perceive sneeze odors in the same way due to differences in olfactory sensitivity. Additionally, if someone consistently notices a particularly strong or unusual smell from their sneeze, it may be worthwhile to consult a medical professional to rule out underlying health issues.

Causes of Sneezing Odors

Sneezing odors can arise from various factors within the nasal passages and beyond. Here are the primary causes of these odors:

  • Bacteria and Infections: The moist environment of the nasal passages can harbor bacteria. Some bacterial infections, like sinusitis, can produce specific odors. For instance, Pseudomonas aeruginosa is known to produce a sweet smell.
  • Fungi: Fungal infections or the presence of mold spores in the nasal passages or sinus cavities can produce a musty or moldy odor.
  • Old or Trapped Mucus: Mucus that has been trapped in the sinuses or nasal passages for extended periods can develop a foul or rotten smell.
  • Diet: Certain foods, especially those high in sulfur like garlic and onions, can influence the odor of a sneeze when their volatile compounds are expelled.
  • Medications and Nasal Sprays: Some nasal sprays or medications, when used, can leave behind a medicinal or chemical odor that becomes noticeable when sneezing.
  • Blood: Tiny amounts of blood in the nasal passages or sinus cavities, often due to a minor injury or dryness, can lend a metallic odor to a sneeze.
  • Poor Dental Hygiene: Issues related to dental health, like gum disease, can cause a foul odor in the mouth which may be noticeable when sneezing.
  • Respiratory Conditions: Certain respiratory conditions, like bronchitis or pneumonia, might influence the smell of a sneeze due to the presence of infected mucus.
  • Tonsillitis or Tonsil Stones: These can produce a foul smell which becomes noticeable when sneezing.
  • Digestive Issues: Conditions like acid reflux or GERD can cause stomach acids to enter the esophagus and throat, possibly influencing the odor of a sneeze.

Note: If someone is consistently bothered by the odor of their sneeze or notices sudden changes, it’s important to consult with a medical professional. Persistent odors, especially foul ones, might indicate an underlying health issue that needs attention.

How to Prevent Sneezes from Smelling

Preventing sneezes from having an unpleasant odor involves addressing the underlying causes of the odor.

Here are steps you can take to ensure fresher sneezes:

  • Maintain Nasal Hygiene: Regularly rinsing your nasal passages with saline solution can help clear out irritants, reduce mucus buildup, and minimize bacterial overgrowth. Neti pots or nasal irrigation kits can be used for this purpose.
  • Stay Hydrated: Drinking enough water helps to thin the mucus, making it less likely to harbor bacteria and become foul-smelling.
  • Good Oral Hygiene: Brush and floss your teeth regularly. Using an antiseptic mouthwash can further reduce bacteria that might cause bad odors when sneezing.
  • Dietary Considerations: Limit the intake of foods known to produce strong odors, such as garlic, onions, and spicy foods if you’re sensitive to them.
  • Change Air Filters: Regularly changing the air filters in your home can reduce the number of irritants like dust and pollen that you inhale.
  • Avoid Smoking: Smoking irritates the nasal passages, can dry out and alter the smell of mucus, and is detrimental to overall respiratory health.
  • Address Allergies: If you have allergies, managing them with antihistamines or other medications can reduce sneezing and associated odors.
  • Check for Infections: If you suspect a sinus infection or any other respiratory infection, see a doctor. Treatment can prevent the buildup of smelly mucus.
  • Evaluate Medications: Some medications can change the smell of your breath and sneezes. If you’ve noticed a change after starting a new medication, consult with your doctor.
  • Stay Away from Irritants: If possible, avoid environments with strong odors, pollutants, or chemicals that can irritate your nasal passages.

Remember: Occasional variations in the smell of your sneezes are normal. However, if you consistently notice a foul or unusual odor, it’s worth consulting a medical professional to ensure there’s no underlying condition requiring attention.

FAQs About Why Sneezes Smell

What is the Biological Function of Sneezing?

Sneezing is a reflex action designed to expel irritants from the nasal passages. It’s the body’s way of removing unwanted particles like dust, pollen, or microbes that can cause infection.

The forceful expulsion helps clear the nasal passages and can even serve as a protective mechanism, preventing these irritants from entering the lungs.

Why Do I Smell Different Odors When I Sneeze?

The odors perceived during a sneeze arise from various sources. The nasal passages can harbor bacteria, fungi, and trapped mucus, all of which can produce specific smells.

Additionally, certain foods, medications, or underlying health conditions can influence the scent of the expelled air and mucus during a sneeze.

Why Do Sneezes Stink?

Stinky sneezes can be attributed to bacteria present in the nasal passages or sinuses. When the moist environment of the nose becomes a breeding ground for bacteria, it can produce foul-smelling compounds.

Sinus infections, trapped old mucus, or issues related to dental hygiene can also contribute to a foul odor during a sneeze.

Why Do Sneezes Smell Good?

While it’s less common to associate sneezes with a pleasant aroma, some people might find the scent of certain expelled compounds agreeable.

For instance, after consuming fragrant foods or spices like cinnamon or certain fruits, the volatile compounds might be released in a sneeze, producing a pleasant scent. Personal olfactory preferences also play a role in perception.

Why Do Sneezes Smell Sweet?

A sweet smell in a sneeze can be associated with specific bacterial infections. One notable bacterium is Pseudomonas aeruginosa, known to produce a fruity or sweet odor.

It’s essential, though, to be aware that a persistent sweet smell might indicate an underlying health issue and warrant a consultation with a medical professional.

Is it Normal for Sneezes to Smell Bad?

Occasional bad-smelling sneezes can be normal, especially if influenced by recent meals, environment, or transient nasal bacteria.

However, consistently foul-smelling sneezes might indicate an underlying issue, such as a sinus infection, dental problems, or tonsillitis.

If the smell persists or is accompanied by other symptoms, it’s advisable to seek medical advice.

Final Thoughts

Sneezing is a reflex action that serves to expel irritants from our nasal passages.

The accompanying smell, however, is a result of the complex mix of mucus, bacteria, and sometimes even remnants of our recent meals or health conditions.

Understanding the sources of these odors not only satisfies curiosity but also underscores the intricate balance of our body’s systems.

John Landry, BS, RRT

Written by:

John Landry, BS, RRT

John Landry is a registered respiratory therapist from Memphis, TN, and has a bachelor's degree in kinesiology. He enjoys using evidence-based research to help others breathe easier and live a healthier life.