A sinus infection causes facial pain and pressure, thick discolored nasal discharge, and congestion that makes it hard to breathe through your nose. These three symptoms form the hallmark of the condition, but a sinus infection can also trigger headaches, fatigue, tooth pain, and a reduced sense of smell that together make you feel far worse than a typical cold.
The Three Main Symptoms
Most sinus infections produce a recognizable cluster of symptoms. Thick, yellow or greenish mucus drains from the nose or slides down the back of the throat as postnasal drip. Your nose feels blocked or stuffy, making mouth-breathing the default. And you feel pain, tenderness, or pressure around the eyes, cheeks, nose, or forehead that intensifies when you bend forward.
These core symptoms overlap heavily with a regular cold, which is why duration matters more than any single symptom when figuring out what you’re dealing with. A cold typically improves within seven to ten days. A sinus infection either persists beyond that window or gets noticeably worse after an initial improvement.
Where the Pain Shows Up
You have four pairs of sinus cavities, and the location of your pain depends on which ones are inflamed. Pressure and aching across your cheeks, sometimes radiating into your upper teeth, points to the maxillary sinuses, the largest pair, sitting just behind your cheekbones. Pain across your forehead suggests the frontal sinuses above your eyebrows. A deep ache between or behind your eyes involves the ethmoid sinuses, smaller cavities near the bridge of the nose. Less commonly, the sphenoid sinuses deeper in the skull produce pain that radiates to the top of the head, the temples, or the back of the neck.
Bending over or straining tends to increase the pain regardless of which sinuses are affected, because the position increases pressure inside the inflamed cavities.
Why Your Teeth Might Hurt
Upper tooth pain during a sinus infection catches many people off guard, sometimes sending them to the dentist before they realize the real cause. The roots of your upper back teeth sit very close to the floor of the maxillary sinuses, and in some people the roots actually extend into the sinus cavity. When those sinuses swell, the inflammation presses directly on or near the tooth roots, creating pain that can feel identical to a dental problem. The giveaway: sinus-related tooth pain usually affects several upper teeth at once rather than one specific tooth, and it tends to worsen when you bend forward or jump.
Loss of Smell and Taste
A dulled or completely absent sense of smell is extremely common with sinus infections. In chronic cases, up to 83% of patients experience some degree of smell loss. This happens in two ways. The simpler cause is congestion physically blocking odor molecules from reaching the smell receptors high in the nasal cavity. The more concerning cause is prolonged inflammation damaging those receptors directly, which can persist after the congestion clears.
What many people describe as “lost taste” during a sinus infection is usually lost smell. Your tongue still detects salty, sweet, sour, and bitter just fine, but flavor perception depends heavily on aromas reaching your nose from the back of your throat while you eat. When that pathway is blocked, food tastes flat and bland.
Other Common Symptoms
Beyond the core trio, sinus infections produce a range of secondary symptoms that vary from person to person:
- Fatigue that feels disproportionate to the severity of the infection, partly from disrupted sleep due to congestion
- Ear pressure or fullness, because the sinuses and ears share drainage pathways
- Cough, often worse at night, triggered by postnasal drip irritating the throat
- Bad breath, caused by bacteria in stagnant mucus sitting in the sinuses and draining into the throat
- Headache that feels dull and constant, distinct from the sharp or throbbing quality of a migraine
- Low-grade fever, more common in bacterial infections
Viral vs. Bacterial: How to Tell the Difference
The vast majority of sinus infections start as viral infections, meaning antibiotics won’t help. Distinguishing viral from bacterial matters because it determines whether you need medical treatment or just time.
Three patterns suggest a bacterial infection has developed. First, symptoms that persist for 10 days or longer without any improvement. Second, severe symptoms from the start: a fever of 102°F or higher along with facial pain and thick nasal discharge lasting three to four days. Third, the “double worsening” pattern, where your symptoms start to improve after four to seven days and then suddenly get worse again, with new fever or increased discharge.
One common misconception: green or yellow mucus does not automatically mean you have a bacterial infection. Both viral and bacterial infections change mucus color. The discoloration comes from immune cells and the enzymes they release, not from bacteria themselves. Mucus color alone is not a reliable way to determine whether you need antibiotics.
When Symptoms Last Months
A sinus infection that lasts 12 weeks or longer qualifies as chronic rhinosinusitis. The symptoms are similar to an acute infection but generally less intense and more persistent. Instead of sharp facial pain, you may have a constant dull pressure. Instead of thick colored discharge, you may notice ongoing postnasal drip. Smell loss tends to be more pronounced and longer-lasting in chronic cases, and fatigue becomes a defining feature rather than a secondary one.
Chronic sinusitis often involves underlying factors like nasal polyps, allergies, or structural issues in the nasal passages. Diagnosing it typically requires imaging or a direct look inside the nose rather than a symptom check alone.
How Symptoms Look Different in Children
Children get sinus infections too, but their symptoms don’t always match the adult pattern. A child is less likely to describe facial pressure or localized pain and more likely to present with a cold that simply won’t go away. The key signs to watch for include nasal discharge and a daytime cough lasting more than 10 days without improving, thick yellow discharge paired with a fever lasting three or four days, swelling or dark circles around the eyes (especially in the morning), and persistent bad breath alongside cold symptoms.
Children also have a harder time articulating what they feel, so increased irritability, poor sleep, and refusing food can be indirect signs. Swelling or redness around the eyes that lasts all day (not just morning puffiness), a severe headache, persistent vomiting, or sensitivity to light are more urgent signs that warrant prompt medical attention.
Symptoms That Signal Something Serious
Sinus infections very rarely spread beyond the sinuses, but the potential complications are serious enough to recognize. The sinuses sit close to the eye sockets and the brain, and infection can occasionally reach these areas.
Redness or swelling around the eye that worsens, vision changes, a bulging eye, high fever with severe headache, stiff neck, confusion, or seizures are all signs of a potentially dangerous complication. These symptoms represent infection spreading to the tissue around the eye, the lining of the brain, or the blood vessels near the sinuses. They require immediate emergency care, not a wait-and-see approach.
What to Expect at a Doctor’s Visit
Diagnosing a sinus infection is largely based on your symptoms and how long you’ve had them. During an office visit, your doctor will typically ask about the timeline and severity, feel for tenderness across your cheeks and forehead, and look inside your nose for swelling, redness, or discharge. In straightforward cases, no imaging is needed. A CT scan or nasal endoscopy is reserved for infections that don’t respond to treatment, keep coming back, or are suspected of being chronic.