A sinus infection typically announces itself with a combination of thick, discolored nasal discharge, facial pain or pressure, and congestion that either lasts longer than 10 days or gets worse after initially improving. While many of these symptoms overlap with a common cold, the pattern and duration are what set a sinus infection apart.
The Core Symptoms
Four symptoms are considered the hallmarks of a sinus infection: nasal blockage or congestion, thick nasal drainage (from the front of your nose or dripping down the back of your throat), facial pain or pressure, and a reduced sense of smell. You don’t need all four, but having at least two or three of these together is the pattern that points toward sinusitis rather than a simple cold.
The nasal discharge is one of the more telling signs. Clear, watery drainage is common with colds and allergies. With a sinus infection, the discharge tends to be thick and discolored, often yellow-green, sometimes appearing more on one side than the other. If you blow your nose and see that kind of discharge consistently for several days, it’s a meaningful clue.
Facial pain from a sinus infection feels different from a regular headache. It’s a deep, pressure-like ache that tends to localize around the specific sinuses that are inflamed. The maxillary sinuses, located in your cheekbones, produce pain in the cheek area and sometimes in the upper teeth. The frontal sinuses, above your eyebrows, cause forehead pressure. And the ethmoid sinuses, between your eyes, create pain or swelling around the bridge of the nose and the eye area. Some people notice the pressure gets worse when they lean forward.
How Timing Tells the Story
Most sinus infections start as viral colds. The virus causes swelling in the sinus passages, mucus builds up, and in some cases bacteria begin to grow in that stagnant environment. This is why the timeline matters so much for figuring out what you’re dealing with.
A typical cold improves on its own within 7 to 10 days. If your symptoms persist beyond 10 days without getting better, that’s the clearest signal that a bacterial sinus infection may have developed. The other major red flag is what doctors call “double sickening”: you start to feel better after a few days of being sick, then your symptoms come back worse. That rebound pattern strongly suggests bacteria have taken hold.
A fever above 100.4°F, particularly when it appears alongside facial pain and discolored discharge, also tips the scale toward a bacterial infection. Colds can cause low-grade fevers, but a higher fever combined with worsening sinus symptoms is a different situation.
Sinus Infection vs. Allergies
Allergies and sinus infections share some frustrating overlap, especially congestion and a runny nose. But there are reliable ways to tell them apart. Allergies cause itching: itchy nose, itchy eyes, frequent sneezing fits. A sinus infection doesn’t itch. If you’re sneezing repeatedly and your eyes are watery and irritated, that’s your immune system reacting to an allergen, not an infection.
Allergies also produce clear, thin, watery discharge. The thick, greenish-yellow discharge typical of a sinus infection is uncommon with allergies alone. Facial pain and pressure are another dividing line. Allergies cause congestion and stuffiness, but the deep, localized ache over your cheekbones or forehead points toward sinusitis. That said, prolonged allergies can eventually lead to a sinus infection by keeping the sinuses swollen and blocked, so the two conditions sometimes overlap.
A Simple Self-Check
You can get a rough sense of sinus involvement by gently pressing on your face. Using your thumb, apply light pressure just below your eyebrows along the bony ridge (where your frontal sinuses sit), then press just to each side of your nose below the cheekbones (where your maxillary sinuses are). If either spot is noticeably tender or painful, that sinus area is likely inflamed. Mild pressure sensation is normal, but sharp tenderness is not.
Another thing to pay attention to is whether your symptoms are one-sided. A sinus infection often affects one side more than the other, producing pain, pressure, or discharge that’s worse on the left or the right. Colds and allergies tend to affect both sides more evenly.
When It Becomes Chronic
Most sinus infections resolve within four weeks, whether on their own or with treatment. But if your symptoms, even mild ones, persist for three consecutive months or longer, that crosses into chronic sinusitis territory. Chronic sinusitis involves the same core symptoms (congestion, drainage, facial pressure, reduced smell) but at a lower, grinding intensity that doesn’t fully go away. It often requires imaging or a direct look inside the nasal passages to confirm, and the treatment approach is different from a short-term infection.
Signs That Need Prompt Attention
Sinus infections rarely become dangerous, but the sinuses sit close to the eyes, brain, and spinal cord. Infections can, in uncommon cases, spread to those areas. Swelling or redness around the eye, vision changes, a severe headache that feels different from typical sinus pressure, a high fever that won’t break, or a stiff neck alongside sinus symptoms are all reasons to get evaluated quickly rather than waiting it out.
Outside of those unusual scenarios, the practical threshold is straightforward: symptoms lasting more than 10 days without improvement, or symptoms that rebound after getting better, warrant a visit to your doctor. Most viral sinus infections clear on their own, but bacterial ones often benefit from antibiotics, and only a provider can make that call.