A persistent foul-smelling nasal discharge merits a doctor visit. This is especially true if others can also smell the odor, if it occurs following an upper respiratory infection, and/or it's accompanied by other symptoms such as facial pressure or tooth pain, says Karen H. Calhoun, MD, FACS, FAAOA, professor in the Department of Otolaryngology, Head and Neck Surgery at the Ohio State University Wexner Medical Center.

While it's not all that common for nasal mucus to have a bad odor, when this does occur, there are two main possible causes, Calhoun says. Yes, a sinus infection. Or, a foreign object can be lodged in the nasal passages.

"A sinus infection is the most common cause of nasal discharge that has an odor, but it can also be caused by a foreign body that's been up in the nose for a while. This is, naturally, more common in children," says Calhoun. In the case of some sort of blockage in the nasal passage, the smell and discharge may only seem to be coming from one side of the nose and not the other. But assuming that your doctor rules out any foreign object stuck in your nose, then it's a pretty safe bet that you're dealing with a sinus infection, also called sinusitis, which typically occurs when the sinus lining becomes inflamed and fluid is trapped there, allowing bacteria to grow.

Symptoms of a Sinus Infection

With a bacterial sinus infection, Calhoun says that you'll probably experience nasal discharge, congestion, and facial pressure for about a week and then the symptoms will seem to be resolving on their own, when they suddenly kick back in and get worse again. Along with the nasal symptoms and odor, it's also common to also experience thick nasal discharge (although it's worth noting that the actual color of the mucus is no longer considered a way to differentiate between viral and bacteria sinusitis). You may also have a fever, headache, earache, sore throat, cough, bad breath, and fatigue.

While your primary care doctor may make a diagnosis of a sinus infection based on your symptoms and a physical exam, an ear, nose and throat doctor, or other specialist, will likely want to look deeper into the cause, particularly if you're experiencing ongoing problems. "Our current gold standard is to visualize the interior of the nose with a small telescope to see if there are the mucosal changes associated with a bacterial infection and/or actual pus in the nose (which we can then culture to tell us about antibiotic sensitivity)," Calhoun says.

Treating and Preventing a Sinus Infection

To treat a sinus infection with foul-smelling discharge, you'll want to clear your nasal passages with steam (such as from the shower or a humidifier) and also use a decongestant. In some cases, taking an antibiotic may also be warranted.

"Anything that prevents swelling of nasal mucosa from blocking drainage routes from the sinuses helps prevent sinusitis," Calhoun says. "So if you have a cold, taking an oral decongestant or using a topical decongestant such as Sudafed, or using a topical decongestant like Afrin® (three days only) can help promote healthy drainage."

For allergies, using an antihistamine or implementing long-term allergy management strategies such as environmental changes and immunotherapy (allergy shots or drops) can be effective.

One caveat: "If you don't have allergies, an antihistamine can work against you by thickening your secretions, making them harder to clear," Calhoun warns. "Nasal irrigation with saline can keep secretions from building up. Mucinex® (guiafenesin) is a mucus-thinning agent that is helpful. And staying well hydrated also keeps mucus thin and draining."

When recurrent sinus infections are a problem, she suggests undergoing allergy testing, since the treatment/prevention strategies are different in allergic and non-allergic patients.

Karen Calhoun, MD, reviewed this article.



Calhoun, Karen H. MD FACS FAAOA. Professor, Department of Otolaryngology-Head and Neck Surgery, The Ohio State University Wexner Medical Center. Email interview 11 June 2013.

Mayoclinic.com. "Acute Sinusitis: Symptoms." The Mayo Clinic. 20 Jan. 2012. Web. 12 June 2013.