Difficulty breathing through the nose, often described as congestion or a stuffy nose, is a common experience. The nose functions as the primary air conditioner for the respiratory system, preparing inhaled air for the lungs. It warms the air, humidifies it, and filters out dust, pollen, and other pollutants. When this process is disrupted, the body shifts to mouth breathing, but the underlying causes range from temporary inflammation to complex physical obstructions.
Common Causes of Acute Congestion
The most frequent causes of nasal congestion involve a temporary inflammatory response within the nasal passages. This inflammation, known as rhinitis, occurs when the immune system reacts to an infection or an allergen. The congestion is primarily caused by the swelling of the internal nasal lining, not mucus alone.
This swelling happens because the small blood vessels within the turbinates, structures inside the nose that regulate airflow, dilate significantly. This process increases blood flow and causes fluid leakage into the surrounding tissues, reducing the space available for air to pass through. The resulting edema creates the sensation of a blocked nose.
Viral infections, such as the common cold, trigger this acute inflammatory cascade. Similarly, allergic rhinitis causes the immune system to overreact to harmless particles like pollen, releasing inflammatory mediators like histamine. This causes rapid swelling, leading to congestion, sneezing, and increased mucus production. Acute sinusitis, inflammation of the sinus cavities typically following a cold, also contributes by blocking the narrow drainage pathways.
Physical and Structural Airflow Blockages
When nasal breathing difficulty is chronic or persistent, the cause is often a physical or structural barrier rather than temporary inflammation. These anatomical issues create a constant impediment to airflow that cannot be fully resolved by addressing swelling alone.
The septum, the wall of cartilage and bone dividing the nose, can be displaced in a condition called a deviated septum. This physical barrier restricts airflow, often making breathing noticeably more difficult on one side, and can result from birth or injury.
Nasal polyps are soft, non-cancerous growths on the lining of the nose or sinuses. Polyps can develop due to chronic inflammation and may grow large enough to completely obstruct the nasal passage, leading to persistent stuffiness and a reduced sense of smell.
Turbinate hypertrophy involves the persistent enlargement of the turbinates, the bony structures covered in soft tissue along the side walls of the nose. Chronic irritation from conditions like year-round allergies or a deviated septum can lead to permanent thickening of the tissue. Unlike the temporary swelling of acute congestion, these structural problems represent a fixed reduction in the airway size.
Everyday Triggers and Situational Effects
Beyond medical conditions, several everyday factors and situational changes can significantly affect nasal airflow. One common experience is the “nasal cycle,” a natural process where the blood vessels in the turbinates alternately swell and shrink, causing one nostril to be more congested than the other. This cycle typically switches every few hours and is a normal physiological function.
Positional effects mean that nasal congestion often worsens when a person lies down, especially at night. When the body is horizontal, gravity causes increased blood flow to the head, which increases the pressure within the nasal blood vessels and further swells the turbinate tissue. This positional congestion can disrupt sleep.
The overuse of certain decongestant nasal sprays, such as those containing oxymetazoline, can lead to rhinitis medicamentosa, or rebound congestion. These sprays work by forcing the nasal blood vessels to constrict, but using them for more than three to five consecutive days causes the tissues to become dependent on the medication. When the spray wears off, the blood vessels overcompensate by dilating even more than before, resulting in severe, persistent stuffiness.
When Nasal Breathing Difficulty Requires a Doctor’s Visit
While most cases of acute congestion resolve on their own, certain symptoms indicate that professional medical evaluation is necessary. If nasal congestion persists for longer than ten days without improvement, it suggests the issue may be a bacterial infection or a chronic condition.
A doctor’s visit is also warranted if the congestion is accompanied by more severe symptoms. These include a high or prolonged fever, or the discharge of greenish-yellow mucus alongside significant facial pain or pressure. Any bloody nasal discharge, especially if it occurs repeatedly or after a head injury, requires immediate medical attention. If difficulty breathing through the nose is severe enough to consistently interfere with sleep or cause chronic mouth breathing, a consultation with a healthcare provider or a specialist, such as an otolaryngologist, is advisable.