A sinus infection typically announces itself with a combination of facial pressure, congestion, and thick nasal discharge that lingers well beyond the timeline of a normal cold. Most colds start improving within three to five days. If your symptoms have persisted for 10 days or more without getting better, there’s a good chance a sinus infection has developed.
The tricky part is that sinus infections and colds share many of the same symptoms early on, so timing and symptom patterns matter more than any single sign.
The Core Symptoms of a Sinus Infection
Doctors look for a specific combination of symptoms when diagnosing sinusitis. You generally need at least two of the following to meet the threshold: thick or discolored nasal discharge (draining from the front of your nose or down the back of your throat), nasal congestion or blockage, facial pain or pressure, and a reduced sense of smell. These are considered the hallmark signs.
Beyond those, several other symptoms commonly show up alongside a sinus infection: headache, ear pressure or fullness, dental pain in the upper teeth, bad breath, cough (especially one that worsens at night), and fatigue. On their own, these supporting symptoms aren’t enough to point to sinusitis, but when they appear alongside the core signs, they strengthen the picture.
Facial pressure is one of the more distinctive symptoms. It tends to settle around your cheeks, forehead, or between your eyes, and it often gets noticeably worse when you bend forward or strain. You can gently press on the area just above the inner corner of your eye or over your cheekbones. If that produces tenderness, it suggests your sinuses are inflamed, though this test on its own isn’t definitive.
Cold or Sinus Infection: How to Tell the Difference
Since most sinus infections start as a common cold, the real question is whether your cold has crossed over into something more. There are two reliable patterns to watch for.
The first is simple duration. Cold symptoms typically peak around day three to five and then gradually improve. If you’re at day 10 or beyond and your congestion, discharge, and facial pressure haven’t budged, that plateau suggests a bacterial sinus infection has taken hold.
The second pattern is called “double worsening.” You come down with what seems like a cold. After a few days you start feeling better. Then, suddenly, your symptoms rebound and get worse again, sometimes with a new fever or a return of thick, discolored discharge. This rebound is a strong signal that bacteria have moved into sinuses that were already inflamed from the initial virus.
What Mucus Color Actually Tells You
Yellow or green mucus is one of the most commonly cited “signs” of a sinus infection, but it’s not as reliable as most people think. Research has consistently shown that mucus color alone cannot distinguish a viral infection from a bacterial one. Your body naturally produces thicker, more discolored mucus as part of the normal immune response to any irritant, including a plain cold or even allergies. Most sinus symptoms are caused by viruses or allergies, not bacteria.
That said, thick discolored discharge combined with other symptoms (persistent congestion, facial pressure, and the timelines described above) does contribute to the overall picture. Just don’t treat green mucus as proof you need antibiotics.
How Symptoms Look Different in Children
Kids don’t always present with the classic adult pattern. In children, the most telling sign is a cough or nasal discharge lasting more than 10 days without improvement. A combination of thick yellow discharge and a fever lasting three or four days in a row also raises concern.
Some signs are more specific to children: swelling and dark circles around the eyes, particularly noticeable in the morning, and persistent bad breath alongside cold symptoms. A severe headache behind or around the eyes that worsens when the child bends over is another red flag. Young children often can’t articulate facial pressure, so ongoing irritability, poor sleep, and a cough that worsens at night are the clues parents tend to notice first.
When Symptoms Turn Serious
The vast majority of sinus infections resolve on their own or with straightforward treatment. Rarely, infection can spread to nearby structures, including the eye socket or the lining of the brain. Seek immediate medical care if you develop any of the following: pain, swelling, or redness around your eyes; double vision or other sudden vision changes; a high fever; a stiff neck; or confusion. These symptoms suggest the infection has moved beyond your sinuses and needs urgent attention.
When a Sinus Infection Becomes Chronic
Acute sinus infections are defined by symptoms lasting less than four weeks. If your symptoms persist for 12 weeks or longer, the condition is reclassified as chronic sinusitis. Chronic sinusitis involves the same core symptoms (thick discharge, congestion, facial pressure, reduced smell) but tends to feel less intense day to day. Fever and sharp facial pain, which are common in acute infections, are often absent or mild in the chronic form. That lower intensity can make chronic sinusitis harder to recognize. Many people chalk it up to “always being congested” or assume they have persistent allergies.
Do You Need a CT Scan or Other Testing?
For a straightforward sinus infection, you probably don’t need imaging. The diagnosis is clinical, meaning a doctor can make it based on your symptoms, their duration, and a physical exam. Imaging guidelines from the American College of Radiology confirm that CT scans aren’t necessary for uncomplicated acute sinusitis.
A CT scan becomes appropriate when symptoms are severe, when complications like eye swelling or intense headache develop, or when infections keep recurring. If chronic sinusitis is suspected, imaging or a nasal endoscopy (a small camera guided into the nasal passages) helps confirm that the sinuses are actually inflamed rather than that something else is causing your symptoms. MRI is reserved for rare situations like suspected fungal infections or when there’s concern about spread to the eye or brain.
A Quick Self-Check
If you’re sitting at home wondering whether what you have is a sinus infection, run through this checklist:
- Duration: Have your symptoms lasted 10 days or more without improving, or did they improve and then suddenly worsen?
- Discharge: Do you have thick, discolored mucus draining from your nose or down your throat?
- Congestion: Is one or both sides of your nose significantly blocked?
- Facial pressure: Do you feel pain or pressure around your cheeks, forehead, or eyes, especially when bending forward?
- Smell: Has your sense of smell noticeably decreased?
If you can check off two or more of those core symptoms and they’ve followed one of the timing patterns described above, a sinus infection is a reasonable explanation. If your symptoms are still within the first week and gradually improving, you’re most likely dealing with a common cold that will resolve on its own.