When you have a sinus infection, the air-filled cavities behind your forehead, cheeks, and eyes become inflamed and swollen. This traps mucus that would normally drain freely, creating pressure, pain, and congestion that can last days to weeks. About 29 million American adults are diagnosed with sinusitis each year, making it one of the most common reasons people visit a doctor.
What’s Happening Inside Your Sinuses
Your sinuses are lined with a thin layer of tissue that produces mucus. Tiny hair-like structures called cilia sweep that mucus toward small drainage openings, keeping the sinuses clean and ventilated. During an infection, the lining swells enough to partially or fully block those openings. Mucus backs up, bacteria or viruses multiply in the stagnant fluid, and the cycle of inflammation worsens.
This is why a sinus infection feels so different from a regular stuffy nose. It’s not just swollen nasal tissue. It’s trapped, pressurized fluid sitting in enclosed spaces right next to your eyes, teeth, and brain. That proximity explains many of the symptoms people find surprising, like tooth pain or a dull ache behind the eyes.
Symptoms You’ll Notice
The hallmark symptoms of a sinus infection are facial pressure or pain, thick discolored nasal discharge, and congestion that makes it hard to breathe through your nose. You may also lose your sense of smell partially or completely. These are considered the core signs, and having two or more of them points strongly toward sinusitis.
But the secondary symptoms often catch people off guard. Ear pressure or fullness, upper tooth pain, bad breath, fatigue, and a cough (especially one that worsens at night from post-nasal drip) are all common. The fatigue in particular can be significant. Your body is fighting an active infection while you’re sleeping poorly due to congestion and discomfort, so feeling wiped out for a week or more is normal.
The location of your pain often reflects which sinuses are affected. Pressure across your forehead points to the frontal sinuses. Pain in your cheeks or upper teeth suggests the maxillary sinuses behind the cheekbones. Deep pain between or behind the eyes can involve the ethmoid or sphenoid sinuses farther back in the skull.
Viral vs. Bacterial: How to Tell the Difference
Most sinus infections start as viral infections, essentially a cold that settles into the sinuses. These typically improve on their own within 7 to 10 days. A bacterial sinus infection is suspected when symptoms persist beyond 10 days without improving, or when they initially get better and then suddenly worsen. That “double worsening” pattern, where you think you’re recovering and then spike a new fever or experience a return of thick discharge, is one of the clearest signals that bacteria have moved in.
Green or yellow nasal discharge alone doesn’t confirm a bacterial infection. Viral infections produce discolored mucus too. The more reliable indicators are the combination of colored discharge, disrupted sleep, and moderate-to-severe symptom intensity. Research on distinguishing viral from bacterial infections found that when both green discharge and sleep disruption were present, the likelihood of a simple viral cold dropped to about 24%, while the absence of both pushed the probability of a plain cold up to 70%.
How Long It Lasts
Sinus infections fall into three categories based on duration. Acute sinusitis lasts less than 4 weeks and is the most common type. Chronic sinusitis persists beyond 12 weeks, sometimes with symptoms that never fully resolve. Recurrent acute sinusitis means you get four or more separate infections per year, each lasting 7 to 10 days.
The gap between acute and chronic isn’t just about time. Chronic sinusitis often involves ongoing low-grade inflammation rather than active infection, and it can stem from structural issues like nasal polyps, a deviated septum, or allergies that keep the sinus openings perpetually narrowed. If your sinus infections keep coming back or never quite clear up, the underlying cause is usually something keeping those drainage pathways blocked.
What Helps at Home
Saline nasal irrigation is one of the most effective things you can do. Rinsing your sinuses with salt water thins trapped mucus, flushes out bacteria and allergens, and reduces the swelling that’s causing the blockage. You can use a neti pot, squeeze bottle, or prefilled container. The key safety rule: never use plain tap water. Use distilled water, sterile water, or water you’ve boiled for five minutes and allowed to cool. Tap water can contain organisms that are harmless in your stomach but dangerous in your sinuses.
To make your own rinse, mix one to two cups of prepared water with a quarter to half teaspoon of non-iodized salt. Table salt contains iodine and anti-caking agents that can irritate the lining. If the solution stings, reduce the salt. Skip nasal irrigation entirely if you have an ear infection, complete blockage of one nostril, or recent sinus surgery. Always clean your irrigation device after each use and let it air dry.
Beyond saline rinses, steroid nasal sprays can meaningfully reduce inflammation. A Cochrane review of clinical trials found that people using nasal steroid sprays experienced symptom improvement at a rate of 73%, compared to 66% with placebo, over 15 to 21 days. Higher doses showed stronger effects. These sprays work by calming the swollen tissue that’s blocking drainage, and they can be used alone or alongside antibiotics when bacteria are involved.
Warm compresses across the face, staying well-hydrated, and sleeping with your head elevated can also ease pressure and help mucus drain. Dry air makes everything worse, so a humidifier in your bedroom at night can keep nasal passages from drying out and crusting over.
When Symptoms Need Medical Attention
Most sinus infections resolve without antibiotics. But you should contact a healthcare provider if your symptoms last longer than 10 days, initially improve and then worsen again, or don’t respond to the home measures described above. Persistent sinus headaches also warrant a visit, since they can sometimes signal complications or a different condition entirely.
Rare but serious complications can develop when infection spreads beyond the sinuses. Orbital involvement, where infection reaches the eye socket, accounts for about 80% of all sinusitis complications because the sinuses sit so close to the eyes. Symptoms like swelling around one eye, vision changes, pain with eye movement, or a bulging eye need urgent evaluation. Intracranial complications like brain abscesses occur in roughly 4% of patients with sinusitis complications. Frontal sinus infections carry the highest risk because the frontal sinuses sit directly against the brain’s frontal lobe. High fever, severe headache, stiff neck, confusion, or sudden vision loss are emergencies.
These outcomes are genuinely rare, but they underscore why a sinus infection that keeps getting worse rather than slowly improving deserves professional attention rather than more patience.