A sinus infection typically announces itself with facial pressure or pain, thick nasal discharge, and congestion that lasts longer than a normal cold. Most colds improve within 7 to 10 days, so the biggest clue is whether your symptoms are sticking around past that window, getting worse instead of better, or both.
The Core Symptoms to Look For
Sinus infections share several symptoms with regular colds, which is why they’re easy to confuse. The key difference is the combination and intensity of what you’re feeling. The symptoms that point toward a sinus infection include:
- Facial pain or pressure around your cheeks, forehead, or between your eyes. This often feels worse when you lean forward.
- Thick nasal discharge that may be yellow, green, or cloudy, sometimes draining down the back of your throat.
- Nasal congestion that makes it hard to breathe through your nose.
- Reduced sense of smell or taste.
- Pain in your upper teeth, which can feel like a toothache even though nothing is wrong with your teeth. The roots of your upper molars sit very close to your maxillary sinuses, so swelling there creates pressure that mimics dental pain.
One particularly telling sign is a foul smell that you notice but nobody else can. This symptom, called cacosmia, is one of the strongest individual indicators of a bacterial sinus infection. Fever above 102°F alongside facial pain and thick discharge also raises the likelihood considerably.
The Timeline Matters Most
Timing is the single most useful tool for figuring out whether you have a sinus infection or just a stubborn cold. Nearly all colds are caused by viruses, and those viruses can inflame your sinuses temporarily. That’s a viral sinus infection, and it usually clears up on its own within 10 days.
A bacterial sinus infection is suspected when your symptoms persist without improvement for at least 10 days after they started, or when you experience what doctors call “double sickening.” That means you started feeling better for a few days and then got noticeably worse again, with returning or worsening congestion, pain, or fever. This pattern of improvement followed by deterioration is a strong signal that bacteria have taken hold in your already-inflamed sinuses.
If you develop a high fever above 102°F along with facial pain and thick discharge that lasts three or more days, that’s a faster route to the same conclusion. You don’t need to wait the full 10 days in that case.
Green Mucus Doesn’t Mean What You Think
One of the most common misconceptions is that green or yellow mucus means you have a bacterial infection and need antibiotics. The color of your mucus is not a reliable way to tell bacterial from viral infections. Both can produce discolored discharge. Green and yellow shades come from enzymes released by your white blood cells as they fight off any type of infection, viral or bacterial.
What matters more is how long you’ve been sick, how you feel overall, and whether things are getting better or worse. If you’ve had yellow or green mucus for more than seven days and you’re still feeling bad or getting worse, that’s when a bacterial infection becomes more likely. The color alone, especially in the first week, tells you very little.
Sinus Infection vs. Allergies
Allergies and sinus infections can both cause congestion and a runny nose, but they feel different in important ways. Allergies typically cause sneezing, itchy eyes, an itchy nose, and thin, watery, clear discharge. Sinus infections cause facial pain or pressure and thicker, discolored discharge. Itchiness is the hallmark of allergies, not infections.
That said, allergies can set the stage for a sinus infection. Prolonged allergic inflammation can block your sinus drainage pathways, creating a warm, moist environment where bacteria thrive. If your usual allergy symptoms suddenly shift to include facial pressure, thicker discharge, or fever, an infection may have developed on top of the allergic inflammation.
A Simple Self-Check
You can do a quick assessment at home. Try leaning forward with your head toward the ground. If you feel a noticeable increase in pressure or throbbing pain around your cheeks, forehead, or eyes, that suggests your sinuses are inflamed and possibly filled with fluid. This happens because bending forward shifts fluid inside the swollen sinus cavities, increasing pressure against the already-irritated walls.
You can also press gently on the areas just below your eyes (over your cheekbones) and on your forehead above your eyebrows. Tenderness in those spots corresponds to your maxillary and frontal sinuses. Pain with light pressure suggests those cavities are inflamed.
Neither of these tests is definitive, but combined with the symptom timeline, they give you a reasonable picture of what’s going on.
Acute vs. Chronic Sinus Infections
Most sinus infections are acute, meaning they develop quickly and resolve within a few weeks. If your symptoms last 12 weeks or more, that crosses into chronic sinusitis territory. Chronic sinusitis isn’t just a long cold. It often involves persistent low-grade congestion, reduced smell, facial pressure, and post-nasal drip that doesn’t fully go away. The causes are different too, frequently involving nasal polyps, structural issues, or ongoing inflammation rather than a single bacterial invader.
If you keep getting sinus infections several times a year, or if your congestion and facial pressure never seem to fully resolve between episodes, that pattern is worth investigating further.
Symptoms That Need Prompt Attention
Most sinus infections, even bacterial ones, resolve without complications. But certain symptoms signal something more serious. Swelling or redness around your eye, especially if one eye looks puffy or swollen compared to the other, can indicate that the infection is spreading beyond the sinuses into the eye socket. A severe headache that doesn’t respond to over-the-counter pain relievers, a very high fever, stiff neck, confusion, or vision changes all warrant immediate medical evaluation. These complications are rare but require fast treatment.