A sinus infection causes facial pain and pressure, thick discolored mucus, and nasal congestion that can last anywhere from a few days to several months. Most sinus infections start as viral infections that resolve on their own within a week, but roughly one in ten progresses to a bacterial infection that may need treatment. Knowing which symptoms to watch for, and how they change over time, helps you figure out what you’re dealing with.
How a Sinus Infection Develops
Your sinuses are air-filled cavities behind your forehead, cheeks, and eyes. They produce mucus that drains through narrow passages into your nasal cavity, flushing out germs in the process. When a cold, allergies, or irritation causes the lining of those passages to swell, mucus gets trapped. That warm, stagnant environment is where infection takes hold.
The key drainage pathway connects your forehead, cheek, and eye-level sinuses. A blockage anywhere along it can trigger inflammation that spreads across multiple sinus cavities at once, which is why sinus infections often cause pain in several areas of the face simultaneously.
The Core Symptoms
Three symptoms define a sinus infection more than any others:
- Thick, discolored mucus. Yellow or green discharge from the nose, or mucus dripping down the back of the throat (postnasal drip). The color alone doesn’t tell you whether the infection is viral or bacterial.
- Nasal congestion. A blocked or stuffy nose that makes it difficult to breathe normally. This often gets worse at night.
- Facial pain and pressure. Tenderness, swelling, or a deep aching sensation around the eyes, cheeks, nose, or forehead. Bending forward typically makes it worse because the shift in position increases pressure in the blocked sinuses.
Symptoms You Might Not Expect
Beyond the obvious congestion and facial pressure, sinus infections cause a surprising range of secondary symptoms. Ear pressure is common because your sinuses and ears share drainage pathways. Headaches, especially across the forehead or between the eyes, often accompany the facial pressure.
One symptom that catches people off guard is toothache. Your largest sinuses sit directly above the upper back teeth, and the roots of those teeth sometimes extend into the sinus cavity itself. When those sinuses become inflamed, the pressure can produce pain that feels exactly like a dental problem. If your upper back teeth ache and you also have congestion, the sinuses are the likely culprit.
Bad breath is another frequent companion. Mucus pooling in the back of the throat creates an environment for odor-causing bacteria. A reduced sense of smell (and by extension, taste), cough, fatigue, and low-grade fever round out the full picture.
Viral vs. Bacterial: How to Tell the Difference
This is the question most people actually need answered, because it determines whether you need medical treatment or just time. Unfortunately, the classic signs people associate with bacterial infection, like green mucus, fever, and headache, are unreliable. They show up with viral infections too.
The real distinguishing factor is timing. A viral sinus infection typically starts improving after five to seven days. A bacterial infection persists for seven to ten days or longer, and often gets worse after the first week instead of better. Doctors use what’s sometimes called the “10-day rule”: if symptoms haven’t improved at all after 10 days from when your cold started, a bacterial infection is the likely explanation.
There’s also a pattern called “double sickening.” You start feeling better around day five, then between days five and ten your symptoms flare up again, sometimes worse than before. That rebound is a strong signal that a bacterial infection has developed on top of the original viral one.
When Symptoms Become Chronic
If your symptoms stretch beyond 12 weeks, the diagnosis shifts to chronic sinusitis. The core symptoms are the same: discolored drainage, nasal obstruction, facial pain or pressure, and a decreased sense of smell. But the experience is different. Chronic sinusitis tends to be less intense day to day than an acute infection, more of a persistent low-grade misery than a dramatic illness. It often involves underlying factors like nasal polyps, a deviated septum, or ongoing allergic inflammation that keep the sinuses from draining properly.
Two or more of those four core symptoms lasting 12 weeks or longer is the standard diagnostic threshold. If you’ve been dealing with some combination of congestion, facial pressure, mucus drainage, and smell changes for three months, you’re in chronic territory and likely need a more thorough evaluation than a standard doctor visit for a cold.
Sinus Infection Symptoms in Children
Children get sinus infections too, but they don’t always describe their symptoms the way adults do. The signs to look for include persistent yellow or green nasal discharge, a cough that lingers (especially at night), facial pain or headache, nasal congestion severe enough to cause mouth breathing or snoring, and fever. Young children may simply seem irritable or more tired than usual without being able to articulate that their face hurts or they can’t smell anything. A cold that seems to drag on well past the usual week, or one that improves and then gets worse again, warrants the same suspicion of bacterial infection as it would in an adult.
How Sinus Infections Are Treated
Most sinus infections are viral and don’t respond to antibiotics. The current guidance from the CDC is “watchful waiting” for uncomplicated cases, meaning you manage symptoms at home and give the infection time to clear. Saline rinses, staying hydrated, steam, and over-the-counter pain relievers for the pressure are the standard approach for the first seven to ten days.
If your symptoms persist beyond that window without improvement, or if they worsen at any point after initially getting better, antibiotic treatment becomes a reasonable consideration. This is a conversation to have with your doctor based on your specific timeline and severity.
Red-Flag Symptoms That Need Urgent Attention
Sinus infections rarely become dangerous, but when they do, the consequences are serious. The sinuses sit close to the eyes and brain, and infection can occasionally spread to those areas. Sharp eye pain, blurry or double vision, a bulging or swollen-shut eye, a severe headache unlike your typical sinus pressure, a stiff neck, or confusion all signal that the infection may have moved beyond the sinuses. These symptoms call for emergency care, not a wait-and-see approach.