The three hallmark signs of a sinus infection are thick, discolored nasal discharge combined with either nasal congestion or facial pain and pressure. A regular cold can cause all of these too, so the real question isn’t just what symptoms you have, but how long they last, how severe they are, and whether they follow a specific pattern over time.
The Three Core Symptoms
Most sinus infections produce a recognizable cluster of symptoms. Purulent (thick, yellow or greenish) discharge from the nose or dripping down the back of your throat is the most consistent sign. This is usually paired with a stuffy nose that makes it hard to breathe, and pain or pressure around your eyes, cheeks, forehead, or upper teeth. The pain often gets worse when you bend forward.
Other common symptoms include a reduced or lost sense of smell, a full or heavy feeling across your face, and fever. You might also notice bad breath, fatigue, or an aching feeling in your upper jaw. None of these symptoms on their own confirms a sinus infection, but the combination of discolored discharge plus congestion or facial pressure is what clinicians rely on most.
How Timing Separates a Cold From a Sinus Infection
A typical cold improves within 7 to 10 days. If your symptoms persist beyond 10 days with no improvement, that’s one of the strongest clinical indicators of a bacterial sinus infection. This is the most widely used rule of thumb, and it’s the one your doctor will likely apply first.
But you don’t always have to wait 10 days. There are two other patterns that point to a bacterial infection earlier:
- Severe onset: A fever of 102°F (39°C) or higher along with thick, discolored discharge right from the start, lasting three to four days, suggests bacteria rather than a virus.
- “Double sickening”: You start to feel better after the first few days, then around day five or six your symptoms get noticeably worse. Your congestion returns, your fever spikes again, or your facial pain intensifies. This worsening-after-improvement pattern is a classic sign that a bacterial infection has developed on top of the original viral cold.
A cold that simply lingers at the same mild level isn’t the same as one that’s actively worsening. The distinction matters because most sinus infections start as viral colds, and only a small percentage become bacterial. If your symptoms are mild, not disrupting your sleep, and slowly fading, you’re more likely dealing with a virus that’s running its course.
Green Mucus Doesn’t Mean What You Think
Yellow or green nasal mucus is one of the most misunderstood symptoms, even among some clinicians. Discolored mucus is not a reliable indicator of a bacterial infection on its own. Both viruses and bacteria trigger the same immune response in your nasal lining, and it’s the concentration of white blood cells and their enzymes that changes the color, not the type of germ involved.
There is one useful timing clue, though. With a viral cold, mucus tends to start clear and become thicker and more colorful several days in as your immune system ramps up. With a bacterial infection, thick, colored mucus is more likely to appear right at the beginning. So if you wake up on day one with heavy green discharge and a high fever, that pattern is more suggestive of bacteria than the gradual color shift you see with a typical cold.
When It’s Actually a Migraine
Many people who think they have recurring sinus infections actually have migraines. This isn’t a rare mix-up. The nerves activated during a migraine are the same nerves that supply your sinuses, eyes, ears, and jaw. That means migraines can cause real nasal congestion, a runny nose, watery eyes, and facial pressure that feels identical to a sinus infection.
A few questions can help sort this out. Does the headache throb or pulse? Does it get worse with physical activity? Do you feel nauseous or become sensitive to light or sound during the episode? If you answer yes to at least two of those, there’s roughly a 93% chance you’re experiencing a migraine rather than a sinus headache. True sinus headaches almost always come with thick, discolored discharge, reduced smell, and often fever. If your “sinus headaches” come without those symptoms, migraine is the more likely explanation.
How Sinus Infections Look in Children
Kids don’t always describe facial pressure or headaches the way adults do, so you have to watch for different clues. The most reliable sign in children is cold symptoms, particularly a runny nose and daytime cough, lasting more than 10 days without any improvement. A combination of thick yellow nasal discharge and a fever lasting three to four consecutive days is another strong indicator.
Children with sinus infections may also develop persistent bad breath (not explained by poor brushing), swelling or dark circles around the eyes that are worse in the morning, and headaches behind the eyes that intensify when bending over. Younger children may simply seem more cranky or tired than usual, which makes the 10-day rule especially useful as an objective marker when other symptoms are vague.
Acute vs. Chronic Sinus Problems
An acute sinus infection is a single episode that typically resolves within a few weeks, with or without antibiotics. Most bacterial cases improve within 10 to 14 days of treatment, and many resolve on their own.
If your symptoms persist for 12 weeks or longer, even at a low level, the diagnosis shifts to chronic sinusitis. This is a different condition with different causes. Chronic sinusitis involves ongoing inflammation of the sinus lining and often relates to structural issues, allergies, or immune factors rather than a single infection. The symptoms are similar, including congestion, facial pressure, reduced smell, and drainage, but they’re constant or cycling rather than appearing in a single defined episode. Chronic sinusitis needs a different treatment approach and usually involves imaging or a direct look inside the nasal passages to assess what’s going on.
Symptoms That Need Prompt Attention
Most sinus infections are uncomfortable but not dangerous. Certain symptoms, however, suggest the infection may be spreading beyond the sinuses. A fever above 103°F, significant swelling or redness around one or both eyes, vision changes like double vision or difficulty seeing, a severe headache that doesn’t respond to over-the-counter pain relief, or a stiff neck are all signs that warrant urgent evaluation. In children, increasing irritability combined with any of these signs is particularly concerning.