The four main symptoms of sinusitis are nasal congestion or obstruction, facial pain or pressure, thick discolored nasal discharge, and a reduced sense of smell. These four signs form the core of how sinusitis is diagnosed clinically, and nearly 29 million adults in the U.S. are affected each year. Understanding what each symptom feels like, why it happens, and how long it lasts can help you tell the difference between a passing cold and something that needs medical attention.
Nasal Congestion or Obstruction
The most recognizable symptom is a blocked or stuffy nose that makes it hard to breathe through one or both nostrils. This happens because the tissue lining your sinuses swells in response to infection or irritation, narrowing the passageways. At the same time, mucus becomes thicker and stickier than normal. The combination of swollen tissue and heavy mucus creates a sensation of fullness or blockage that can persist for days or weeks.
Unlike the brief stuffiness of a mild cold, sinus-related congestion tends to feel deeper and more constant. You may notice it worsens when you lie down, making sleep difficult. Mouth breathing, snoring, and a muffled quality to your voice are all common side effects.
Facial Pain and Pressure
Sinusitis causes a dull, aching pressure that settles in specific areas of your face depending on which sinuses are inflamed. You have four pairs of sinus cavities, and each one produces pain in a different spot:
- Frontal sinuses: pain across your forehead
- Maxillary sinuses: pain in your cheekbones or upper teeth
- Ethmoid sinuses: pain around the bridge of your nose
- Sphenoid sinuses: pain behind your eyes or in your ears
The pain often worsens when you bend forward, because the shift in position increases pressure inside the inflamed cavities. Many people mistake maxillary sinus pain for a toothache, which is worth keeping in mind if your upper teeth ache alongside other sinus symptoms.
Thick, Discolored Nasal Discharge
Sinusitis typically produces a thick, yellowish or greenish nasal discharge that drains from the front of the nose or down the back of the throat (postnasal drip). This is one of the symptoms people most associate with a sinus infection, though the color alone doesn’t reliably distinguish a viral infection from a bacterial one.
During a normal cold, mucus usually starts clear and watery, then gradually thickens and turns yellow or green over several days. That color change comes from immune cells and their enzymes accumulating in the mucus as your body fights the infection. With a bacterial sinus infection, thick colored mucus more often appears early, sometimes within the first day or two of illness, rather than building up over time. The postnasal drip version of this discharge can trigger a persistent cough, sore throat, or a bad taste in the mouth.
Reduced Sense of Smell
A diminished or completely lost sense of smell is the fourth hallmark symptom and one that often gets overlooked. Swelling in the upper nasal passages blocks odor molecules from reaching the smell receptors located high inside your nose, in an area called the olfactory cleft. In more severe or chronic cases, the inflammation itself damages the specialized nerve cells responsible for detecting scent, which can make smell loss persist even after the infection clears.
Because taste and smell are closely linked, many people notice food tastes bland or “off” while they have sinusitis. This usually resolves as swelling goes down, but in chronic sinusitis, especially when nasal polyps are present, the loss can be longer lasting.
Other Symptoms You May Notice
Beyond the four primary signs, sinusitis commonly brings a collection of secondary symptoms. These include headache, ear pain or fullness, aching in the upper teeth, cough (especially at night from postnasal drip), sore throat, bad breath, and fatigue. None of these on their own point to sinusitis, but when they show up alongside the four main symptoms, they reinforce the picture.
Viral vs. Bacterial: How Duration Changes the Picture
Most sinus infections start as viral infections, essentially a cold that has settled into the sinuses. Viral sinusitis typically runs its course in under 10 days. If your symptoms persist beyond 10 days without improving, or if you develop a high fever (102°F or higher) with facial pain and thick discharge lasting three to four days, the infection is more likely bacterial.
There’s also a pattern called “double sickening” that strongly suggests a bacterial infection. This is when you start feeling better after five or six days of a typical cold, then suddenly worsen again with new fevers, increased headache, or heavier nasal discharge. That relapse pattern is one of the most reliable signs that bacteria have taken hold and antibiotics may be warranted.
Warning Signs of Serious Complications
In rare cases, a sinus infection can spread to nearby structures, particularly the eye socket or the brain. This is more common in adolescents and young adults with frontal sinusitis. Symptoms to take seriously include vision changes or blurry vision, a bulging or swollen eye, limited eye movement, severe headache that feels different from typical sinus pressure, a stiff neck, or a high fever that isn’t responding to treatment. These situations require emergency evaluation, as the infection may have moved beyond the sinuses into areas where it can cause permanent damage if not treated quickly.