The four main symptoms of sinusitis are nasal congestion, thick nasal discharge, facial pain or pressure, and a reduced sense of smell. These are the cardinal signs used to diagnose rhinosinusitis, and having at least two of them for 12 weeks or longer points to the chronic form of the condition. In acute cases, the same four symptoms appear but resolve in under four weeks.
Nasal Congestion
Nasal obstruction is often the most noticeable symptom. The lining of your sinuses swells in response to infection or irritation, narrowing the passages that normally allow air to flow freely. This swelling can also block the small openings (ostia) that drain mucus from each sinus cavity, creating a cycle where trapped fluid fuels more inflammation and more congestion. You may find it difficult to breathe through one or both nostrils, and the blockage often shifts sides depending on your position.
Thick or Discolored Nasal Discharge
The second hallmark is mucopurulent drainage, which simply means thick, cloudy, or yellowish-green mucus. It can drain from the front of your nose or slide down the back of your throat (postnasal drip), causing throat irritation and a persistent urge to clear your throat. The color itself doesn’t reliably distinguish a viral infection from a bacterial one, but the volume and persistence of discharge help clinicians gauge severity.
When discharge is accompanied by a high fever of 102°F or above and lasts three or more days from the start of illness, it may signal a bacterial sinus infection rather than a simple cold. Another telltale pattern is “double-sickening,” where symptoms start to improve after five or six days, then suddenly worsen with increased discharge, headache, or fever.
Facial Pain and Pressure
Sinusitis pain results from inflamed tissue pressing against nerve endings in the sinus walls. Sensory nerve fibers in the nasal lining release signaling molecules that trigger vasodilation and amplify the pain response, which is why the ache tends to feel deep, throbbing, and hard to pinpoint. Swollen ostia that trap fluid intensify the pressure further.
Where you feel the pain depends on which sinuses are involved:
- Frontal sinuses: pain across the forehead
- Maxillary sinuses: pain in the cheekbones or upper teeth
- Ethmoid sinuses: pain along the bridge of the nose
- Sphenoid sinuses: pain behind the eyes or in the ears
Because the roots of the upper back teeth sit very close to, or even extend into, the maxillary sinus cavity, a sinus infection can produce a convincing toothache. If your upper molars ache on both sides and you also have congestion, the sinuses are a more likely culprit than a dental problem.
Reduced Sense of Smell
Swollen tissue and trapped mucus physically block odor molecules from reaching the smell receptors high inside your nasal cavity. In acute sinusitis, this loss is usually partial and temporary, resolving as the infection clears. In chronic sinusitis, especially cases involving nasal polyps, smell loss can persist for months and sometimes affects taste as well, since the two senses are closely linked. A diminished sense of smell that doesn’t bounce back after congestion resolves is one of the clearest markers distinguishing chronic sinusitis from a lingering cold.
Acute vs. Chronic Sinusitis
Acute sinusitis lasts fewer than four weeks and usually follows a viral upper respiratory infection. Fever is more common in acute cases. Most episodes clear on their own without antibiotics, since the majority are viral in origin. A bacterial cause becomes more likely when symptoms persist 10 days or more without improvement, or when the double-sickening pattern appears.
Chronic sinusitis is diagnosed when at least two of the four main symptoms persist for 12 weeks or longer despite treatment. It is typically not caused by bacteria, so antibiotics rarely help. The underlying drivers are more often persistent inflammation, allergies, or structural issues like a deviated septum or polyps. Pain tends to be less intense in chronic cases, replaced by a constant low-grade pressure and fatigue, while congestion and smell loss often dominate.
How Symptoms Differ in Children
Children don’t always present the same way adults do. Younger kids rarely complain of facial pressure or smell loss. Instead, the most reliable signs are a runny nose lasting longer than seven to ten days and a cough that is worse at night. Older children and teens look more like adults, with congestion, discharge, and cough, but they still tend to report facial pain less consistently. A cold that simply won’t quit, especially with nighttime coughing, is the pattern to watch for.
Symptoms That Need Urgent Attention
Sinus infections can, in rare cases, spread to nearby structures. Swelling or redness around the eyes, double vision or other vision changes, a stiff neck, confusion, or a very high fever are signs that infection may be affecting the eye socket or the tissue surrounding the brain. These symptoms call for immediate medical evaluation.