Common causes are:

• Respiratory infection

• Upper respiratory infection caused by pharyngitis (an inflammation or infection of the larynx in the throat)

• Cold

• Flu

Other more permanent causes are:

• Allergies

• Hay fever

• Allergic rhinitis

• Sinus infection

• Chronic sinusitis

• Adenoid conditions

• Adenoiditis

• Vasomotor rhinitis

• Nasal polyp

• Nasal tumor

• Benign nasal polyp

• Nasal tumor

• Deviated septum

• Nasal injury

• Nasal abnormality

Some could be caused by medications like some blood pressure medications, beta blockers and over dose estrogen.

Prevention

If your blocked nose is caused by flu or cold which is the most common attack for most people and if this is the usual cause i.e. you are prone to attack of cold and flu then it is obvious that you have a weak lung condition. Then the obvious preventive measure is to strengthen the lungs by consuming herbs rich in omega-3 acids (alpha-linolenic acid) and lung warming herbs like Folium Perilla Frutescens, Semen Sinapis Alba, Radix Pinella Ternata, Cinnamomi Ramulus, Cinnamomum Cassia, Rhizoma Zingiberis and Radix Glycyrrhiza Glabra.

Treatment

For immediate solution you have to get your nose unblocked because breathing through your mouth is difficult and result in dehydrated throat. The key is to stop the fluid from flowing, arrest the inflammation and if the phlegm is yellow then you have to stop the infection. Used a holistic product to treat such problem. Used a holistic herbal antibiotic liquid that has the following functions:

• Anti-inflammatory: reduce swelling of the wound
• Anti-exudates: prevent the production of skin fluid to allow the wound to dry faster
• Antibiotic: cleanse the skin of harmful bacteria and virus
• Anti-toxin: it neutralizes poison produced by the decaying tissue , bacteria or virus

Spray such a liquid into the nose or use a cotton bud to coat the nostril with a good dose of the liquid to allow the vapor to do the work.