The hallmark symptoms of a sinus infection are thick, discolored nasal discharge combined with nasal congestion, facial pain or pressure, or both. These symptoms can overlap significantly with a common cold, which is why timing and severity matter just as much as the symptoms themselves. Most sinus infections start as viral colds and resolve on their own, but knowing what to watch for helps you recognize when something more is going on.
The Core Symptoms
A sinus infection produces a predictable cluster of symptoms. Thick nasal discharge, often yellow or green, is the most defining feature. This discharge can drain from the front of your nose or slide down the back of your throat (sometimes called post-nasal drip), triggering a persistent cough or throat irritation. Nasal congestion accompanies it, making it difficult to breathe through one or both nostrils.
Facial pain or pressure is the other major symptom, and it tends to feel different depending on which sinuses are affected. Pain across your forehead points to the frontal sinuses. Aching in your cheeks or upper teeth suggests the maxillary sinuses, the largest pair, which sit just above your upper jaw. Pain behind the bridge of your nose involves the ethmoid sinuses, while deeper pain behind your eyes or at the top of your head can signal the sphenoid sinuses, which are tucked further back in the skull.
A reduced or lost sense of smell is common, particularly with chronic infections. Fatigue, a general feeling of being unwell, and low-grade fever round out the typical picture. The facial pain often worsens when you lean forward, because the shift in position increases pressure in already-swollen sinus cavities.
Why Your Teeth Might Hurt
Upper tooth pain catches many people off guard during a sinus infection, but it has a straightforward explanation. The roots of your upper back teeth sit very close to the floor of the maxillary sinuses, and in some people, the roots actually extend into the sinus cavity. When those sinuses become inflamed and swollen, the pressure bears directly on nearby tooth roots, producing what feels exactly like a toothache. The giveaway is that multiple upper teeth ache at once rather than a single tooth, and the pain tends to shift when your congestion changes. If you’re unsure, a dentist can rule out cavities or gum disease first.
Cold vs. Sinus Infection: The 10-Day Rule
Since most sinus infections begin as colds, the real question is when a cold crosses the line. Two patterns signal that shift. The first is duration: cold symptoms typically start improving after three to five days. If your symptoms persist beyond 10 days without getting better, that suggests a bacterial sinus infection has developed.
The second pattern is called “double worsening.” You catch a cold, start to feel better after a few days, then suddenly get worse again with renewed congestion, thicker discharge, and returning facial pressure. That rebound strongly suggests bacteria have taken hold in the stagnant mucus your cold left behind.
Here’s what happens biologically. Your sinuses have tiny openings that normally drain mucus into the nasal passages. When a cold inflames the lining of those openings, they swell shut. Mucus gets trapped, and bacteria that would normally be flushed out begin multiplying in the stagnant fluid. That’s why facial pressure alone, without the thick discharge, isn’t enough to call it a sinus infection.
Symptoms in Children
Children don’t always present the same way adults do. Rather than complaining of facial pressure, kids with sinus infections tend to show a persistent runny nose lasting longer than 7 to 10 days, with thick green or yellow discharge (though it can also be clear). A nighttime cough is especially common, caused by mucus draining down the back of the throat while lying down. Some children also have a daytime cough that comes and goes. Irritability, fatigue, and swelling around the eyes may be more noticeable than in adults, partly because children’s sinuses are still developing and sit closer to the eye sockets.
Acute, Subacute, and Chronic Infections
Sinus infections are classified by how long they last, and the distinction matters because the symptoms shift over time:
- Acute: Resolves completely within 4 weeks. This is the most common type and often follows a cold.
- Subacute: Lasts between 4 and 12 weeks. Symptoms are similar to acute but tend to be less intense and more grinding.
- Chronic: Persists for 12 weeks or longer. The dominant symptoms are congestion, reduced sense of smell, and ongoing drainage rather than the sharp facial pain of an acute infection. Fatigue becomes a bigger factor.
- Recurrent: Four or more separate acute episodes per year, with at least 10 symptom-free days between each one.
Most acute sinus infections, whether viral or bacterial, are self-limited. Viral cases typically resolve within 7 to 10 days with symptom management alone, and even bacterial infections often clear without antibiotics. Treatment for uncomplicated cases focuses on relieving symptoms: saline rinses to flush mucus, staying hydrated, and using decongestants or pain relievers as needed.
Symptoms That Need Immediate Attention
In rare cases, a sinus infection can spread beyond the sinuses into surrounding structures, including the eye socket or the membranes around the brain. Watch for these warning signs:
- Swelling, redness, or pain around the eyes
- Double vision or other changes in your eyesight
- High fever
- Stiff neck
- Confusion
These symptoms suggest the infection may have spread and requires urgent medical evaluation. An infection reaching the eye socket can threaten vision, and spread to the brain’s protective membranes can cause meningitis. These complications are uncommon, but they develop quickly, so the timeline matters.