A blocked nose is a common complaint but the reasons why it may occur can be quite varied. Most of us associate a blocked nose with an acute infection like the common cold or a sudden change in the weather that clears after a short period of time. However, for some people a blocked nose is a daily occurrence that either momentarily resolves for certain parts of the day or may never ease at all. It is important to understand what exactly a blocked nose means as the term is often used loosely for a range of upper respiratory tract conditions.

Meaning of a Blocked Nose

A blocked nose or stuffy nose is simply nasal congestion. This means that the nasal cavity is obstructed to some extent that affects the passage of air in and out of the nose. Although the paranasal sinus may also become congested at times, if it does not interfere with the nasal passages then it is not a blocked nose. However, often the sinuses are also affected with a blocked nose.

Other symptoms frequently occur with a blocked nose. Some of these symptoms are a direct consequence of the congestion, while other features are concomitant symptoms due to the underlying cause. A person with a blocked nose may have difficulty with the sense of smell, a runny nose, post nasal drip and a nasal tone of the voice as a consequence of the congestion. Concomitant symptoms that may occur with certain causes of a blocked nose may include watery eyes, sneezing, sore throat, pain at the bridge of the nose, facial pain and headaches.

Most cases of a blocked nose are due to an excess build up of nasal mucus. The inner lining of the nasal cavity is a mucous membrane that normally produces moderate amounts of mucus to moisturize the cavity and trap dust and microbes. With inflammation, the mucuous membrane produces excessive amounts of mucus. This is known as rhinitis.

Nasal Infections

Infections affecting the lining of the nasal cavity are common. These are mainly viral in origin like the common cold. Sometimes other infectious agents may be responsible such as bacteria and in rare instances even fungi. Bacteria more often infect the paranasal sinuses where it can thrive within a relatively sheltered environment but the infection usually extends into the nasal cavity. A runny or blocked nose can persist for several days to weeks after the infection resolves.

Allergies

Some people are hypersensitive to inhaled substances. These allergens can trigger inflammation when it comes in contact with the nasal mucosa. Many of these allergens do not pose a problem to non-sensitive people. At most it may cause minor irritation of the nasal mucosa when inhaled in large amounts. However, in an allergic person, even exposure to a small amount of the allergen can trigger sneezing, watery eyes, a runny nose and nasal congestion. Common allergens include :

  • Dust
  • Pollen
  • Animal hair/fur
  • Mold
  • Cockroach particles

These individuals also react more aggressively to the irritants discussed below. In allergic children, even some ingested allergens (food and drink) can cause a blocked nose. This type of nasal condition is known as allergic rhinitis, and may be seasonal or perennial (throughout the year).

Irritants

A number of irritants can inflame the nasal mucosa even in a person who does not have allergies. The degree of inflammation depends on the duration of exposure as well as the amount of the irritant that enters the nasal cavity. Sneezing followed by excess mucus production leading to a blocked nose are common symptoms. Some  common nasal irritants include :

  • Smoke from fires or cigarettes
  • Industrial gases
  • Strong perfumes and other strong odors
  • Excessive dust
  • Organic and inorganic dust in the workplace
  • Spices (airborne)
  • Chlorinated water

Hormones

This type  of nasal inflammation (rhinitis) is mainly seen in women. It occurs when there is a significant fluctuation in the female hormone levels. Hormonal rhinitis tends to occur in pregnancy or with the use of oral contraceptives. It can also arise in other hormone-related problems like hypothyroidism (underactive thyroid gland). Hormone-induced rhinitis can occur even in a person without a history of allergies and usually resolves once the hormone problem resolves.

Foreign Bodies

An object within the nasal cavity can cause a blocked nose and inflame the nasal mucosa. Both the object and the excess nasal mucus causes congestion. It is not common for a foreign body to be found in the nasal cavity of adults. Usually it is a problem among children. This is mainly seen in infants who insert smaller objects into the nose during play. If it remains in the nasal cavity for a period of time, it can lead to the development of secondary infections of the nose.

Growths and Anatomical Defects

Various growths in the nasal cavity and defects in the anatomy of the nose can also contribute to a blocked nose. Nasal polyps are a type of growth that can lead to excess mucus production and even obstruct the nasal passages if it is large. A deviated septum, perforated septum and tumors within the nose or paranasal sinuses may be other anatomical defects and growths that can contribute to a blocked nose. Some of these problems not only triggers excess mucus production but also impedes mucus drainage and increases the chance of secondary nasal infections.

Change in Weather

A dry climate, cold and rainy weather can also trigger a runny nose and nasal congestion. Even moving into an air conditioned room that is very cold can trigger a blocked nose. This type of reaction to changes in weather is seen with vasomotor rhinitis. Even drinking very cold drinks can be a problem. A change to hot weather is less likely to pose a problem but if a runny nose and nasal congestion occurs in spring or summer, it is more likely to be seasonal allergic rhinitis.

Foods and Drinks

A number of different food and drinks can cause a blocked nose. This is known as gustatory rhinitis, where excess mucus production occurs with consuming certain food items and beverages. In fact most of us experience a runny nose when we eat large amounts of very spicy foods. But people with gustatory rhinitis react much faster and the degree of mucus production can quickly congest the nose. Although a variety of foods and drinks may serve as a trigger, it is spicy foods that are by far the main culprit.

Medication

A number of different drugs can cause rhinitis as a side effect. Sometimes it simply worsens pre-existing chronic rhinitis. This type of medication-induced rhinitis usually resolves once the drug is discontinued. At times it is medication meant to treat rhinitis that can also be the cause. It is usually with the overuse of nasal sprays. This type of rhinitis is known as rhinitis medicamentosa or rebound rhinitis. It can be short-lived or even chronic as a result of the condition worsening once the medication suppressing the rhinitis is discontinued.

Nose Picking

Although it seems like a fairly harmless act, picking your nose can actually lead to nasal congestion. The nasal mucosa is very delicate and easily irritated or injured. Picking your nose can trigger inflammation of the nasal mucosa marked by sneezing and a runny nose. As with other types of rhinitis, the excess mucus can cause a blocked nose. However, it is short-lived if there is no further irritation in the nasal passages. Chronic nose picking on the other hand can lead to more serious problems like a perforated nasal septum.


Article reviewed by Dr. Greg. Last updated on February 27, 2013