The most common symptoms of a sinus infection are thick nasal discharge, a blocked or stuffy nose, facial pain or pressure, and a reduced sense of smell. These can range from mild and short-lived to persistent and disruptive, depending on whether the cause is viral, bacterial, or chronic inflammation. Most sinus infections start as a common cold, so recognizing when symptoms cross into sinus territory helps you know what you’re dealing with.
The Core Symptoms
Sinus infections produce a recognizable cluster of symptoms. The hallmarks are thick, discolored nasal discharge (yellow or green), nasal congestion or obstruction, a feeling of fullness or pressure in the face, facial pain, decreased sense of smell, and sometimes fever. These are considered the primary indicators, and having two or more of them points toward sinusitis rather than a simple cold.
Beyond those, several secondary symptoms often show up: headache, ear pain or pressure, bad breath, upper tooth pain, cough, and fatigue. These don’t confirm a sinus infection on their own, but they frequently accompany one. The tooth pain catches many people off guard, since it has nothing to do with dental health. It’s referred pain from inflamed sinuses sitting just above the upper jaw.
Where It Hurts Depends on Which Sinus Is Affected
You have four pairs of sinus cavities, and the location of your pain or pressure maps directly to which one is inflamed:
- Frontal sinuses (forehead): Pain across your forehead, often worse when leaning forward.
- Maxillary sinuses (cheeks): Pain in your cheekbones or upper teeth.
- Ethmoid sinuses (between the eyes): Pain along the bridge of your nose.
- Sphenoid sinuses (behind the eyes): Pain behind your eyes or deep in your ears.
Many people feel pressure in more than one area at a time, since multiple sinuses can be inflamed simultaneously. The pain typically worsens when you bend over or lie down, because the change in position increases pressure on swollen tissue.
How Viral and Bacterial Infections Feel Different
Most sinus infections are viral, meaning they follow the same trajectory as a cold. Symptoms ramp up over two to three days, peak, and gradually improve within seven to ten days. No antibiotics help here, and the infection resolves on its own.
A bacterial sinus infection is suspected in two specific patterns. The first is when symptoms persist for at least 10 days without improving at all. The second is called “double worsening,” where you start to feel better after a few days and then get noticeably worse again. That bounce-back is a strong signal that bacteria have taken hold in sinuses that were already swollen and poorly draining from the initial viral infection. Current guidelines recommend a period of watchful waiting even for bacterial infections, since many resolve without antibiotics.
Chronic Sinusitis: When Symptoms Last Months
When sinus symptoms persist for 12 consecutive weeks or longer, the condition is classified as chronic sinusitis. The four cardinal symptoms are the same core group: facial pain or pressure, reduced or lost sense of smell, nasal drainage, and nasal obstruction. Having at least two of these for that duration meets the threshold.
Chronic sinusitis feels different from an acute infection in practice. The pain is usually duller and more constant rather than sharp. Fatigue becomes a more dominant complaint because months of poor sleep, mouth breathing, and low-grade inflammation wear people down. The loss of smell can be partial or complete, and it often affects taste as well, since the two senses are closely linked. Thick mucus draining down the back of the throat (postnasal drip) can cause a persistent cough, a sore throat, and nausea, particularly in the morning.
How Symptoms Look Different in Children
Kids with sinus infections don’t always present the way adults do. A child is less likely to complain of facial pressure and more likely to show a persistent cough, bad breath, irritability, low energy, and swelling around the eyes. The classic sign is a cold that drags on beyond 10 to 14 days, sometimes with a low-grade fever, paired with thick yellow-green nasal drainage.
Headaches from sinusitis are uncommon in children under six. In younger kids, crankiness and fatigue are often the most visible clues. Postnasal drip can trigger nausea or vomiting in children more readily than in adults, and the bad breath tends to be more noticeable because children are less likely to mask it.
Sinus Infections That Start With a Tooth
About one in five cases of chronic sinusitis originates from a dental problem rather than a cold or allergies. This is called odontogenic sinusitis. An infected tooth, a failed root canal, or even a dental implant that extends into the sinus floor can introduce bacteria directly into the maxillary sinus.
The telltale signs are symptoms that hit only one side of your face, a foul smell or taste, and cheek pain on the same side as a problematic tooth. If you’ve had recurring sinus infections that don’t respond to typical treatment, and especially if they’re always on the same side, a dental cause is worth investigating.
Symptoms That Signal a Serious Complication
Sinus infections rarely become dangerous, but when they do, the infection has typically spread beyond the sinus cavities into nearby structures. Symptoms that require immediate medical attention include swelling or redness around the eyes, double vision or other vision changes, a high fever, a stiff neck, and confusion. These can indicate the infection has reached the eye socket or the tissues surrounding the brain. Vision problems from a sinus infection that spreads to the eye socket can cause lasting damage if not treated quickly.