Understanding the Nose: More Than Just Your Sense of Smell

Medically reviewed by Dr. Baraa Alnahhal, MD | Last reviewed: October 7, 2026

Figure 1: The external features and internal structures of the human nose.

Quick Answer: What is the nose?

The nose is a pyramid-shaped structure of bone, cartilage and fatty tissue that begins the breathing process, with two nasal cavities separated by a septum. [1] It filters air through cilia and nose hairs, warms and moistens air with the turbinates and detects scents through specialized nerve cells. [1] Hydration, hygiene and avoiding irritants like smoke keep it healthy. [1]

What the research says

• Large-volume saline rinses may help people with chronic sinus problems, but the evidence is limited. A Cochrane review of two randomized trials (116 adults) found that daily large-volume (150 ml) hypertonic (2%) saline irrigation improved disease-specific quality of life more than usual care, by 6.3 points on a 0–100 scale at 3 months (95% CI 0.89–11.71) and by 13.5 points at 6 months (95% CI 9.63–17.37). The authors rated the evidence as low to very low quality, and 23% of people in the saline group reported side effects, including nosebleeds (Chong et al., Cochrane Database of Systematic Reviews, 2016). [2]

• Stronger saline may help the nose heal after sinus surgery. A meta-analysis of 7 studies (479 adults with chronic rhinosinusitis) found that, compared with regular (isotonic) saline, hypertonic saline irrigation after endoscopic sinus surgery reduced nasal crusting at 30–45 days (RR 0.65, 95% CI 0.49–0.87) and lowered the persistence of swollen, polyp-like mucosa at 14–21 days (RR 0.53, 95% CI 0.43–0.65) (Lima et al., Brazilian Journal of Otorhinolaryngology, 2024). [3]

• The proof that HEPA filters ease nasal allergy symptoms is limited. A Cochrane review of 9 trials (501 people with dust-mite allergy), two of which tested HEPA filters, found that seven of the nine trials reported lower dust-mite loads. However, the trials were small and mostly of poor quality, so the authors could not make firm recommendations about dust-mite avoidance for allergic rhinitis (Sheikh et al., Cochrane Database of Systematic Reviews, 2010). [4]

Overview of the Nose

The nose is a remarkably sophisticated organ that acts as the body's primary gateway for oxygen. [1] While it is most famous for its role in the sense of smell, its daily operations are essential for respiratory health and vocal resonance. By conditioning the air we inhale, the nose ensures that the delicate tissues of the lungs are not exposed to dry, cold, or contaminated air.

The Multifaceted Functions of the Nose

The human nose is constantly at work, performing several vital tasks simultaneously. When you inhale, the nose immediately begins warming and moistening the air, making it comfortable for the rest of the respiratory tract. [1] It also serves as a high-efficiency filter, using a combination of nose hairs and microscopic cilia to trap dirt, allergens, and pathogens before they can reach deeper into the body. [1]

Furthermore, the nose contributes significantly to how you sound when you speak, providing the necessary resonance for your unique voice. [1] The olfactory organs located within the upper nasal passages house specialized nerve cells that communicate directly with the brain, allowing you to detect and distinguish a vast array of smells. This sensory input is not only important for enjoying food but also for detecting environmental hazards.

Function	Primary Role
Air Entry	Oxygenates the body through the respiratory system
Filtering	Removes germs, dust, and allergens using cilia and hairs
Conditioning	Warms and moistens air for lung protection
Olfaction	Detects smells through specialized internal nerve cells
Resonance	Shapes the unique sound of your speaking voice

Internal Anatomy and Complex Structures

While the external part of the nose—the root, dorsum, and apex—is what we see, the most complex work happens inside. The nasal cavities are hollow spaces where air flows, lined with sensitive mucus membranes. [1] These cavities are separated by the septum, a wall of bone and cartilage [1] that can sometimes be deviated, leading to breathing difficulties.

Within these cavities lie the turbinates, or conchae, which are folds of tissue that increase the surface area for warming and moistening air. The nose is also connected to the paranasal sinuses, which are air-filled pockets that produce the mucus necessary to keep the nasal passages moist. [1] This intricate system is supported by cilia, tiny hairlike structures that move trapped particles toward the nostrils for removal. [1]

Common Nasal Conditions and Symptoms

The nose is susceptible to a variety of conditions, with nasal congestion being the most frequent. [1] Congestion occurs when allergens or pathogens—such as viruses, bacteria, or fungi—cause the nasal passages to become inflamed. [1] Other common issues include chronic sinusitis, hay fever, and structural problems like a deviated septum or nasal valve collapse. [1]

Symptoms of nasal disorders can vary widely depending on the underlying cause. While stuffiness and a runny nose are common, individuals may also experience pain or pressure around the face, a cough, or even a total loss of the sense of smell. [1] Recognizing these signs early is key to seeking effective treatment from an otolaryngologist, also known as an ENT specialist.

Condition	Common Symptoms
Nasal Congestion	Stuffiness, runny nose, inflammation
Chronic Sinusitis	Facial pain, pressure, postnasal drip
Deviated Septum	Difficulty breathing, frequent nosebleeds
Hay Fever	Sneezing, sore throat, itchy eyes

Figure 2: Visualizing how inflammation and structural issues affect nasal airflow.

Essential Care and Nasal Hygiene

Maintaining nasal health is a proactive process that involves both environmental management and direct hygiene practices. One of the most important steps is avoiding irritants like cigarette smoke and ensuring your home environment is clean. [1] Using HEPA filters can help remove airborne dust and allergens from indoor air, [1] although research on how much this improves nasal symptoms is limited. [4]

Figure 3: Key strategies for maintaining a healthy and functional nose.

Hydration is also critical, as drinking plenty of water helps keep the mucus membranes moist. For those in dry environments, using a humidifier or performing regular nasal irrigation with a saline spray or neti pot can prevent the nasal cavities from becoming overly dry and irritated. Use only distilled, sterile, or boiled and cooled water for rinsing, never untreated tap water, because tap water can contain germs that are safe to drink but can cause rare, serious infections in the nose. It is also advised to be careful when removing nose hairs, as they serve as an important first line of defense against airborne debris. [1]

Conclusion

The nose is a vital organ that plays a central role in our respiratory health, sensory experience, and communication. By understanding its complex anatomy and the essential functions it performs, we can take better care of this respiratory gateway. Consistent hygiene and prompt attention to nasal symptoms ensure that the nose can continue its important work of filtering and protecting our bodies.

Next Steps

If you suffer from chronic congestion, frequent nosebleeds, or persistent sinus pressure, consult with an otolaryngologist. A professional evaluation can help diagnose structural issues or chronic infections, providing you with a clear path to improved nasal health and easier breathing.

Frequently Asked Questions

What is the primary function of the nose?

The nose warms, moistens, and filters the air you breathe while also providing your sense of smell.

What are the parts of the nose you can see?

The visible parts include the nasal root (top), the nasal dorsum (middle), and the nasal apex (tip).

What are turbinates?

Turbinates are folds inside the nasal cavities that help warm and moisten air and aid in drainage.

How does the nose filter air?

The nose uses nose hairs and tiny hairlike structures called cilia to trap dirt, dust, and allergens.

What is the nasal septum?

The septum is the wall of bone and cartilage that separates the two nasal cavities.

What are the paranasal sinuses?

The paranasal sinuses are air-filled pockets connected to the nasal cavities that produce mucus to keep the nose moist.

What causes nasal congestion?

Nasal congestion is usually caused by inflammation of the nasal passages due to allergens, viruses, bacteria, or fungi.

What is a deviated septum?

A deviated septum is a condition where the wall between your nasal cavities is crooked, which can make breathing difficult.

How can I keep my nose moist?

Drinking plenty of water, using a humidifier, and applying saline nasal sprays are effective methods.

Is it safe to remove nose hairs?

You should be very careful, as they filter dirt; removing them entirely can increase the risk of breathing in debris.

What is nasal irrigation?

Nasal irrigation is the process of using saline water to clean and moisten the nasal cavities, often with a neti pot. Use only distilled, sterile, or boiled and cooled water for rinsing, never untreated tap water, because tap water can contain germs that are safe to drink but can cause rare, serious infections in the nose.

What does an ENT specialist do?

An otolaryngologist (ENT) diagnoses and treats conditions affecting the ear, nose, and throat.

What is anosmia?

Anosmia is the medical term for the total loss of the sense of smell.

Why does my voice sound different when my nose is stuffed?

The nose provides resonance for your voice; when blocked, that resonance is lost, changing your sound.

When should I see a doctor about a nosebleed?

You should seek medical advice if you experience frequent nosebleeds or if a nosebleed is difficult to stop.

Sources

1. Cleveland Clinic. Nose. Cleveland Clinic. Last updated July 29, 2024. https://my.clevelandclinic.org/health/body/21778-nose

2. Chong LY, Head K, Hopkins C, et al. Saline irrigation for chronic rhinosinusitis. Cochrane Database Syst Rev. 2016;4(4):CD011995. PMID: 27115216. DOI: 10.1002/14651858.CD011995.pub2

3. Lima AD, Giffoni RB, Arguelles-Hernandez J, et al. Effectiveness of hypertonic saline irrigation following functional endoscopic sinus surgery: a systematic review and meta-analysis. Braz J Otorhinolaryngol. 2024;91(1):101517. PMID: 39504674. DOI: 10.1016/j.bjorl.2024.101517

4. Sheikh A, Hurwitz B, Nurmatov U, et al. House dust mite avoidance measures for perennial allergic rhinitis. Cochrane Database Syst Rev. 2010;(7):CD001563. PMID: 20614426. DOI: 10.1002/14651858.CD001563.pub3

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Medical disclaimer

The information provided in this article is for educational purposes only and is not intended as medical advice. Always seek the guidance of a qualified healthcare provider regarding any medical condition or treatment.