The hallmark signs of a sinus infection are facial pain or pressure, thick nasal discharge, and congestion that persist beyond the typical cold timeline of seven to ten days. Most sinus infections start as a common cold and resolve on their own, but knowing what to look for helps you tell the difference between a virus running its course and something that needs more attention.
The Core Symptoms
A sinus infection, also called sinusitis, shares many symptoms with a regular cold but tends to be more intense and longer lasting. The main signs include thick, discolored nasal discharge (yellow or green rather than clear), a blocked or stuffy nose, facial pain or pressure, and a reduced sense of smell. You may also notice fatigue, a low-grade fever, or a general feeling of being unwell that lingers well past the point where a cold would have cleared up.
The discharge color matters. Clear, watery, drippy mucus points more toward allergies or the early stages of a cold. Yellow or green discharge signals a more significant inflammatory process and is one of the clearest signs that an infection, rather than simple irritation, is at play.
Where the Pain Shows Up
You have four pairs of sinus cavities, and which ones are inflamed determines where you feel the pain. Infection in the frontal sinuses causes pain across your forehead. The sphenoid sinuses, deeper in the skull, produce pain behind the eyes or in the ears. Ethmoid sinus inflammation creates pressure at the bridge of your nose. And the maxillary sinuses, the largest pair, cause aching in the cheekbones or upper teeth.
That last one catches people off guard. The roots of your upper back teeth sit very close to the maxillary sinus floor, and some roots actually extend into the sinus cavity itself. When those sinuses swell, the pressure can feel identical to a toothache. If you develop upper tooth pain alongside nasal congestion and facial pressure, the sinuses are a likely culprit. A dentist can rule out cavities or gum disease first, and if the teeth are healthy, a sinus infection is the next thing to consider.
The pain typically worsens when you bend forward or lie down, because both positions increase pressure in the inflamed cavities.
The Cough That Won’t Quit
A persistent cough during a sinus infection usually isn’t coming from your lungs. It’s driven by post-nasal drip: excess mucus gathering at the back of your throat and triggering the cough reflex. You might feel a tickle or a lump in the back of your throat, a constant urge to clear your throat, or notice hoarseness and a gurgling quality to your voice.
This cough tends to be worse at night. When you lie flat, gravity stops helping mucus drain forward through your nose, so more of it slides down the back of your throat. If you find that your cough is mild during the day but keeps you awake at night, post-nasal drip from inflamed sinuses is a strong possibility.
Viral vs. Bacterial: The Timeline Tells You
Most sinus infections are viral, meaning antibiotics won’t help and the infection will clear on its own. The key question is how long symptoms last and how they behave over time.
A viral sinus infection generally follows the arc of a cold: symptoms peak around days three to five, then gradually improve over a week to ten days. A bacterial sinus infection is suspected when symptoms persist beyond ten days without improvement, or when they follow a pattern called “double sickening.” That’s when you start to feel better after the initial cold, then suddenly worsen again, with symptoms returning more severely than the first round.
If your runny nose, stuffy nose, and facial pain haven’t budged after ten days, or if you experienced that rebound worsening, a bacterial infection is more likely and may warrant treatment.
How It Differs From Allergies
Allergies and sinus infections overlap enough to be confusing, but a few features help separate them. Allergies tend to produce itchy, watery eyes and a clear, runny nose. The itchiness is the key differentiator: sinus infections don’t typically cause itchy eyes or an itchy nose. Allergies also follow seasonal patterns or flare up around specific triggers like pet dander or dust.
Sinus infections, by contrast, bring more pronounced facial pain and pressure, discolored discharge, and sometimes fever. If you’re experiencing congestion with itchiness and clear mucus, allergies are the more likely explanation. If you have congestion with facial pressure, thick yellow or green discharge, and no itchiness, a sinus infection fits better.
Signs in Children
Children get sinus infections too, but the symptoms look different depending on age. Younger children may simply have a runny nose that lasts longer than seven to ten days, along with a cough that’s mainly noticeable at night with occasional daytime episodes. They’re less likely to complain of facial pain and more likely to just seem generally cranky or unwell.
Older children and teenagers present more like adults, with nasal discharge lasting beyond ten days, coughing, and one symptom parents often notice first: bad breath. Persistent halitosis in a child with a lingering cold is a useful clue that the infection has moved into the sinuses. Because young children can’t always describe pressure or pain, the duration of symptoms and the presence of nighttime coughing are the most reliable signs to watch for.
Warning Signs of a Serious Complication
Sinus infections rarely become dangerous, but the sinuses sit close to the eyes and brain, so infection can occasionally spread to those areas. Seek immediate medical attention if you notice swelling or redness around the eyes, double vision or other visual changes, swelling of the forehead, a severe headache that feels different from typical sinus pressure, a stiff neck, confusion, or a high fever. These signs suggest the infection may have moved beyond the sinuses and requires urgent evaluation.