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When is Nasal Drainage Considered Allergies or a Sinus Infection?

Written by Dr. Arjuna Kuperan · Updated April 8, 2026 Rhinologist · Diplomate, American Board of Otolaryngology – Head and Neck Surgery

Is your throat achy and sore? Are you literally sick and tired of coughing? Post nasal drip may be to blame. Post nasal drip is simply, fancy medical terminology for mucus running down the back of your throat, which can irritate your throat causing that stubborn cough or a sore throat. Nasal drainage can start out as a simple runny nose that can develop due to a multitude of factors like weather changes, the common cold, flu, allergies and sinus infections. Since there are many possible causes, how can people differentiate between nasal drainage caused by allergies versus a sinus infection?

What are the Differences?

Even though both conditions share similarities such as runny noses, nasal congestion, and sore throats, there are key differences that will help you better diagnose your condition.

Post nasal drip caused by allergies (Allergic Rhinitis) often have accompanying symptoms like sneezing, an itchy nose, and teary/itchy eyes. It is also a seasonal condition that most commonly affects children and young adults.

Post nasal drip induced by a sinus infection (Sinusitis) is when your nasal cavities become infected, swollen and inflamed by a virus or bacteria. Symptoms include facial pressure or pain around the nose, eyes, forehead and upper jaw. Mucus associated with a sinus infection is usually thicker, cloudy and can have a yellowish or greenish color to it. Sinus infections also may have lingering symptoms long after treatment such as a persistent cough and a sore throat.

Which Treatments are Available?

Allergic post nasal drip is treatable with a steroid nasal spray that helps reduce swelling in the nasal passage which contributes to congestion. Antihistamines are used to relieve symptoms like sneezing and itchiness, while decongestants are regularly prescribed for congestion. Antibiotics can be administered to deal with nasal drainage caused by sinus infections, but also steroid nasal sprays, antihistamines, and decongestants are prescribed similarly to allergy treatments. However nasal decongestants are not recommended to be used for more than three days because it can cause a rebound effect that leads to worsening symptoms. A helpful tip for people suffering from post nasal drip is to sleep upright or with their head elevated which has been known to reduce the intensity and frequency of coughs during the night and early morning.

Still Have Questions?

If you are experiencing nasal drainage either from allergies or a sinus infection or are unsure of your condition, please consult a local Rhinologist. Administering treatments for an allergic post nasal drip will not effectively treat your health issue if it’s Sinusitis or the other way around. Untreated sinus infections can lead to more serious health concerns like Asthma, Mucoceles, eye infections and even brain infections. If you have any questions regarding post nasal drip or
any of the conditions mentioned above, please feel to call Houston Advanced Nose and Sinus at 713-791-0700 to ask Dr. Arjuna Kuperan for advice or a consultation.

About Dr. Arjuna Kuperan

Rhinologist · Houston Advanced Nose & Sinus

Board certification

American Board of Otolaryngology – Head and Neck Surgery (verify)

Education and training

Undergraduate: Brown University, B.A. Political Science 2004
Medical school: State University of New York Buffalo School of Medicine MD 2008
Post-doctoral training, Otolaryngology – Head and Neck Surgery, Rutgers New Jersey Medical School 2013
Fellowship, Advanced Endoscopic Sinus and Skull Base Surgery, University of Miami Miller School of Medicine 2014

Memberships

American Rhinologic Society

Awards