What Is Nasal Congestion?

Nasal congestion, commonly called blocked or stuffy nose, refers to blockage of nasal passages caused by swelling of nasal mucous layer. Apart from nasal congestion, there are other causes of blocked nose.

Causes of Nasal Congestion

A cause of blocked nose may be suspected from symptoms, their duration, circumstances preceding blockage and effect of treatment trials. When the cause is not obvious, a doctor should be visited. Main causes include:

  1. Infections
  2. Allergies 
  3. Non-allergic rhinitis: emotions, cigarette smoke, medications, irritant gases, hormones, pregnancy, drug addiction, spicy foods…
  4. Poisoning

1. Infections

In infections, blocked nose is usually accompanied by yellowish/greenish discharge

  • In common cold, the nose can be blocked and runny for about a week. Usually there is no fever.
  • Flu (including bird and swine flu) presents with fever, headache, muscle pains, cough and blocked nose lasting from few days to less then few weeks in most cases.
  • Infections of lower respiratory system, like chest cold (acute bronchitis) and pneumonia may also cause runny nose and cough.
  • Childhood infections, like measles or rubella, present with rash, headache, muscular pains, fever and runny nose lasting about 2 weeks.
  • Chronic sinusitis usually presents with blocked nose and pain in the cheeks and front that, if not treated, may last from few weeks to several months. Treatment depends on the cause (viral, bacterial or fungal infection, allergy, nasal polyps, etc).
  • In infectious mononucleosis, which mainly affects children and young adults, fever, fatigue, sore throat, enlarged lymph nodes in the neck, armpits and groin typically appear. Blocked nose, rash and painful liver and spleen may also be present. Symptoms may last from 1 to 2 months. Hospitalization and supportive treatment is sometimes needed.
  • Mucormycosis is fungal infection affecting individuals with low immunity (chronic diabetes, malnutrition, AIDS, chemotherapy, etc.), caused by inhaling moldspores, commonly present in the air. Besides nasal congestion, sinuses, facial bones, eyes, brain or lungs may be affected. Fever and cough may appear. Treatment is with intravenous anti-fungal drug amphotericin B.

2. Allergies (Allergic Rhinitis)

In allergic rhinitis, blocked nose is accompanied with nasal itch and watery discharge.

  • Allergy to pollens (hay fever), dust mites, molds and other inhaled particles usually present with runny and itchy nose, sneezing, cough, wet and itchy eyes. Symptoms appear in bouts and may last as long the trigger exists (in hay fever at any time from early spring to late autumn). 
  • Food allergies only occasionally result in blocked nose but rather in tingling or swollen lips, itchy throat, itchy skin and diarrhea, appearing few minutes to several hours after a meal and lasting from several minutes to few hours
  • Allergy to medications may present with symptoms like in food allergies, or trigger severe response with nasal congestion, difficulty breathing or fainting. Symptoms last as long medication is taken. Medications may also cause blocked nose by other mechanisms. 
  • Hair dye allergies may present with severe face, scalp or neck swelling, redness, itchiness and, rarely, with nasal congestion. Symptoms may last from few hours to several days. 

3. Non-infectious, Non-allergic Rhinitis

Blocked nose with watery discharge, without nasal itch appearing year-round is characteristic for non-allergic rhinitis.

  • Vasomotor rhinitis (vasomotor = related to nerves that control size of vessels; rhinitis = inflammation of the nose) is a condition with nasal congestion without nasal itch, resembling allergic rhinitis (see above) where no allergens can be identified by skin tests. Symptoms may be triggered by certain odors (perfumes, cigarette smoke), bright lights, emotions, temperature or barometric pressure changes, etc. Diagnosis is with exclusion of common allergies. Treatment is with topical corticosteroids, antihistamines and anticholinergic medications. 
  • Systemic disease like severe kidney disease, diabetes, Wegener’s granulomatosis or sarcoidosis can cause blocked nose.
  • Gustatory rhinitis presents with runny nose after ingesting hot or spicy foods or alcohol. This is usually not due to food allergy and typical allergic symptoms like tingling lips, itchy throat or skin are not present.
  • Gastric acid in gastro esophageal reflux disease (GERD) may irritate nasal mucosa and cause its swelling. This usually occurs in small children, especially after a large meal or in the morning.
  • Hormonal rhinitis may appear in 2nd month of pregnancy – it usually disappears shortly after childbirth. Hypothyroidism may also present with runny nose.
  • Medications that can cause nasal congestion as a side effect: non-steroid anti-rheumatic drugs (NSAIDs) like aspirin and ibuprofen, some anti-hypertension medications, sedatives, antidepressants, oral contraceptives, drugs used in erectile dysfunction to name only few.
  • Morphine, heroin or other drugs withdrawal may result in watery nasal discharge, dilated pupils, rapid breathing, strong desire to drug, anxiety, shakiness, hot flashes, diarrhea .
  • Chronic sniffing of cocaine may result in “cocaine nose“: frequent rubbing of nose, watery nasal discharge, loss of sensation of smell, nasal bleeding and nose deformities.
  • Overuse of nasal decongestant sprayscan, paradoxically, result in severe nasal congestion (rhinitis medicamentosa).
  • Inhalation of some environmental or occupational gases like ammonia (NH4), chlorine (Cl2), formalin (water solution of formaldehyde – CH2O), hydrogen sulfide (H2S), nitrogen dioxide (NO2), ozone (O3), phosgene (COCl2) and sulphur dioxide (SO2) may cause nasal congestion.
  • Non-allergic rinitis with eosynophilia syndrome (NARES). Eosinophils are present in the blood like in allergy, but skin allergy tests are negative. The cause is not known.

4. Poisoning

  • Some poisonous plants may cause nasal congestion.

Rare Causes of Stuffy Nose

  • In atrophic rhinitis (rhinitis sicca, dry rhinitis, ozena), a rare condition mainly affecting old people, destruction of nasal lining (supposedly due to bacterial infection) causes nasal congestion, purulent discharge, crusts, post nasal drip, itchy throat and foul odor.
  • Mastocytosis
  • Hemochromatosis
  • Systemic capillary leak syndrome
  • Charlin’s syndromeneuralgiaof the nasal branch of the trigeminal nerve presenting with one side runny nose, pain in the inner eye corner and itchy eye. 

Related Articles:


Article reviewed by Dr. Greg. Last updated on April 26, 2014