Sinus infection symptoms can mimic a common cold for the first several days, which is why so many people wait too long to seek care — or seek antibiotics they don't actually need. Recognizing the difference between a viral upper respiratory infection, allergic rhinitis, and acute bacterial sinusitis is the first step toward the right treatment. This guide walks through the clinical signs, how to differentiate from a cold or allergies, and red flags that mean you should skip telehealth and go straight to in-person care.

The core sinus infection symptoms

Acute sinusitis is inflammation of the paranasal sinuses. According to the American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) clinical practice guidelines, the cardinal features are facial pressure or pain (over the cheeks, between the eyes, or in the forehead), nasal congestion or obstruction, thick discolored nasal discharge (yellow or green), decreased sense of smell, maxillary tooth pain, fever in some cases, and fatigue or cough.

The Centers for Disease Control and Prevention (CDC) notes that most sinus infections are caused by viruses and resolve without antibiotics. The key clinical question is not "do I have a sinus infection?" but "is this viral or bacterial?"

Sinus infection vs. cold vs. allergies

Common cold (viral URI): symptoms peak at days 3–5 and improve by day 7–10. Nasal discharge often starts clear and may thicken mid-illness, but improvement is the trajectory.

Allergic rhinitis: symptoms are bilateral, include itchy eyes and sneezing, and respond to antihistamines. No fever, and discharge stays clear.

Acute bacterial sinusitis: duration and pattern matter most. Read more on how clinicians make this call in our guide to bacterial vs. viral sinusitis. The Infectious Diseases Society of America (IDSA) defines three diagnostic patterns for acute bacterial rhinosinusitis: symptoms persisting 10 days or longer without improvement; severe onset with fever of 39°C (102°F) or higher with purulent discharge or facial pain for at least 3–4 consecutive days; or "double sickening" — initial improvement around days 5–6 followed by worsening.

If your symptoms fit one of these patterns, you may be a candidate for antibiotics. Our overview of first-line sinus antibiotics explains the options.

Red flags: when telehealth is not enough

Most sinus infections are safely managed by a licensed physician via telehealth. A small subset require in-person evaluation or emergency care. Seek immediate, in-person evaluation for vision changes (double vision, blurred vision, eye swelling), severe headache with neck stiffness or photophobia, neurological symptoms (focal weakness, seizures, altered mental status), severe unilateral facial swelling or redness, or any sinus symptoms in immunocompromised patients (poorly controlled diabetes, chemotherapy, organ transplant). These complications are uncommon but serious. The NIH lists orbital and intracranial complications as the leading reasons for hospitalization from acute sinusitis.

Getting treated for sinus infection symptoms

If your symptoms match the IDSA criteria for bacterial sinusitis — or if you simply need a licensed doctor to evaluate them — CodyMD makes the process simple. Text a US-licensed physician, describe your symptoms (duration, severity, fever, double sickening, allergies), and if a prescription is clinically warranted, it's sent to your pharmacy in 1 hour. The visit is $49 flat, no insurance required. For more on what to expect, see our guide to the CodyMD process.

Bottom line on sinus infection symptoms

Facial pressure, thick discolored discharge, and nasal congestion are the hallmarks of a sinus infection, but duration and trajectory determine whether antibiotics are appropriate. Most cases are viral. If your symptoms have lasted 10 days without improvement, started severely, or worsened after initial improvement, a licensed doctor can review your case and prescribe the right treatment — in 1 hour, by text.