Sufferers of post-nasal drip know the symptoms well. The dry cough, itchy, runny nose, and persistent dripping in the back of the nose and throat are unmistakable signs of irritating post-nasal drip. Allergies are one of the most common causes of chronic post-nasal drip. The main culprits can be found outside in nature, and inside a home or workplace.
Post-nasal drip is usually associated with a condition known as rhinitis, which refers to swelling and inflammation of the nasal and sinus lining. The symptoms are generally due to an inability to quickly clear excess mucus from the nasal passages. Allergies can set off rhinitis and post-nasal drip because an allergic reaction tends to produce more mucus than the body can rapidly eliminate.
Allergy-related causes of chronic post-nasal drip can come in the form of seasonal allergies to outdoor irritants or chronic allergies spurred by allergens found in the home or office. Seasonal allergies, also known as hay fever, occur at various times of the year and are set off by allergens such as pollen and grass. Spring and summer are common seasons for this type of allergy because of the abundant pollen in the air and grass particles floating around after lawns are mowed.
Recurring or permanent allergies generally come from irritants found inside the home or in the workplace. Dust, dust mites, and pet dander are the biggest offenders when it comes to chronic post-nasal drip caused by indoor allergens. Some office allergy sufferers point to mold as the main cause of allergic reactions when symptoms only occur while at work.
Some non-allergy causes of rhinitis and chronic post-nasal drip include poor air quality, quick temperature fluctuations, and spicy foods. Irritants such as smog, pollution, and car exhaust can lead to faster blood flow in the nasal passageways and increased nasal secretions. Unlike an allergic reaction, this is a temporary response to a specific agent such as strong detergent or fragrance smells, or smoke from cigarettes, pipes, or cigars. Symptoms caused by these irritants usually go away when the annoyance is removed.
On rare occasions, post-nasal drip may be a side effect of certain medications. Drugs used to treat anxiety, high blood pressure, erectile dysfunction, and some types of oral birth control have been thought to cause post-nasal drip. Drug interference is rarely the cause of post-nasal drip, however, and a physician can usually determine when a prescription medication is causing rhinitis and associated symptoms.