The hallmark symptoms of a sinus infection in adults are nasal congestion, thick or discolored nasal discharge, and facial pain or pressure. Most sinus infections start as viral infections that resolve on their own within 7 to 10 days, but recognizing the full range of symptoms helps you distinguish a routine case from one that needs medical attention.
The Three Primary Symptoms
Across major clinical guidelines, three symptoms consistently define a sinus infection: nasal congestion or blockage, nasal discharge (running from the front of the nose or dripping down the back of the throat), and facial pain or pressure. If you have at least two of these, a sinus infection is the likely cause. A reduced or lost sense of smell and fever are also considered primary indicators, though they occur less often than the core three.
The nasal discharge can be clear, white, yellow, or green. Many people assume that green or yellow mucus automatically signals a bacterial infection, but this isn’t well supported by evidence. Colored discharge happens during viral infections too, as your immune system sends white blood cells to fight the infection. The color alone shouldn’t drive treatment decisions.
Where the Pain Shows Up
The location of your facial pain often corresponds to which sinus cavities are inflamed. Adults have four pairs of sinuses, and each produces a somewhat different pain pattern.
- Maxillary sinuses (cheekbones): Pain below the eyes that can spread to the upper teeth. Pressing on the area just below the eye socket tends to make it worse.
- Frontal sinuses (forehead): Pain across the forehead and around the eyebrows. The inner corner of the eye and the bridge of the nose may feel tender to the touch.
- Ethmoid sinuses (between the eyes): A headache felt behind the nose, often described as deep pressure between the eyes.
- Sphenoid sinuses (behind the eyes): A deeper headache that can radiate to the back of the head. This is the least common type but often the most uncomfortable.
Pain frequently worsens when you bend forward, because the shift in position increases pressure in the inflamed cavities. Many people also notice that the pain is worse in the morning after lying flat overnight.
Secondary Symptoms You Might Not Expect
Beyond the classic trio, sinus infections produce a range of symptoms that can be confusing if you don’t connect them to your sinuses. Postnasal drip, where mucus constantly drains down the back of your throat, is extremely common and often triggers a sore throat, a persistent cough (especially at night), and bad breath. The cough tends to be unproductive, meaning you’re not bringing up much mucus despite the irritation.
Upper tooth pain catches many people off guard. The roots of your upper molars sit very close to the floor of your maxillary sinuses, so when those sinuses swell, the pressure can mimic a toothache. If the pain spans several upper teeth rather than a single tooth, your sinuses are the more likely culprit. Ear fullness or muffled hearing can also occur because the sinuses and middle ear share drainage pathways. When those pathways swell shut, pressure builds in the ear.
Fatigue and a general feeling of being unwell are common, particularly with bacterial infections. A reduced sense of smell and taste often accompanies the congestion, since airflow to the smell receptors at the top of the nasal cavity gets blocked.
Viral vs. Bacterial: How to Tell the Difference
The vast majority of sinus infections are viral, meaning they’ll resolve without antibiotics. Distinguishing viral from bacterial matters because it determines whether treatment will help. The CDC identifies three patterns that suggest a bacterial infection:
- The 10-day rule: Symptoms persist for 10 days or more without any improvement.
- Severe onset: A fever of 102°F (39°C) or higher, along with facial pain and nasal discharge, lasting three to four consecutive days.
- Double sickening: Symptoms seem to improve after four to seven days, then suddenly worsen again with new fever, increased congestion, or worsening facial pain.
If none of these patterns apply, your infection is almost certainly viral. Typical viral sinus infections peak around days three to five, then gradually improve. Antibiotics won’t shorten a viral infection and carry their own side effects, so the timeline matters.
When Symptoms Last 12 Weeks or Longer
If your symptoms persist for 12 weeks or more, the condition is classified as chronic sinusitis. The symptoms overlap with acute infections but tend to be less intense and more grinding. Two or more of the following need to be present: thick or discolored drainage, nasal congestion, facial pain or pressure, and a decreased sense of smell.
Chronic sinusitis also brings subtler symptoms that can be hard to pin down. Unexplained taste changes, dizziness, and a persistent low-grade malaise are all associated with it. Some people develop chronic ear fullness or notice their hearing seems slightly diminished. Because the symptoms are milder than an acute infection, many adults live with chronic sinusitis for months before seeking evaluation, assuming they simply have ongoing allergies or frequent colds.
Symptoms That Need Immediate Attention
Sinus infections very rarely cause dangerous complications, but infection can occasionally spread to nearby structures, including the eyes and brain. Seek care immediately if you experience any of the following alongside a sinus infection:
- Swelling, redness, or pain around one or both eyes
- Double vision or other changes in your eyesight
- A high fever that doesn’t respond to typical measures
- A stiff neck
- Confusion or difficulty thinking clearly
These symptoms can indicate that the infection has spread beyond the sinuses. Orbital complications (around the eye) are the most common serious complication in adults, and they respond well to treatment when caught early.