Congestion, facial pressure, a runny nose, and headaches can all point in different directions, which is why it can be difficult to tell whether you have a sinus infection, allergies, or a cold. These conditions often share symptoms, but they do not follow the same pattern and they are not treated the same way.
The most useful clues are not found in any single symptom. What matters more is how long the symptoms have lasted, whether they are improving or getting worse, whether itching is present, and whether symptoms return after initially getting better. Those details help a physician distinguish between a viral illness, allergic rhinitis, and a possible bacterial sinus infection.
Understanding those differences can also help explain when antibiotics may or may not be appropriate, when watchful waiting makes sense, and when persistent or worsening symptoms should be evaluated by a doctor.
Three conditions, three different time courses
A cold moves on a schedule. The Centers for Disease Control and Prevention (CDC) page on the common cold puts the symptom peak within two to three days and says colds usually last less than a week, though symptoms can persist 10 to 14 days. A cold can still be running at day 10.
Clinicians define acute rhinosinusitis by duration rather than cause. The StatPearls chapter on acute sinusitis places acute disease under four weeks, subacute and chronic above that, and says those cut-offs rest more on consensus than empirical research. Duration names no virus, bacterium or allergen.
The pattern behind allergic rhinitis follows exposure instead of a clock: StatPearls puts roughly 20 percent of cases as seasonal, 40 percent perennial and 40 percent both. Symptoms tied to a particular week describe a trigger rather than a course, so comparing sinusitis symptoms vs cold on duration alone settles little. Sinusitis is more common from early fall to late spring, nationally rather than locally.
The features that sit in each set of diagnostic criteria
For acute bacterial rhinosinusitis (ABRS), the 2015 adult sinusitis clinical practice guideline from the American Academy of Otolaryngology-Head and Neck Surgery Foundation (AAO-HNS) names purulent nasal drainage accompanied by nasal obstruction, facial pain, pressure or fullness, or both.
AAO-HNS’s allergic rhinitis guideline asks instead for a history and examination consistent with an allergic cause plus at least one of nasal congestion, runny nose, itchy nose or sneezing. A 2023 rapid evidence review in American Family Physician describes the examination findings, among them clear rhinorrhea, as often nonspecific, gaining value combined with the history.
Nasal or ocular pruritus sits in the allergic rhinitis row of the differential table in a 2023 review of chronic rhinosinusitis and in none of its infectious rows, a fact about definitions, not a measurement. No source quantifies how well itchy eyes and nose separate them, so itch is worth reporting, not a test that settles anything.
Two rows of that table are neither allergic nor infectious: rhinitis medicamentosa, rebound congestion after intranasal decongestants stop, and irritant rhinitis. Both are reasons a medication review belongs in history.
Discharge color settles less than it seems
AAO-HNS corrects the detail most people arrive with: nasal purulence alone does not indicate a bacterial infection, and discolored nasal discharge signals inflammation and is not specific for infection. The coloration comes from neutrophils rather than bacteria. A 2016 review of adult acute rhinosinusitis in American Family Physician reports a positive likelihood ratio of 1.5 for colored nasal drainage.
Fever, where two guideline bodies disagree
AAO-HNS declined to include fever as a cardinal sign of ABRS, citing a sensitivity and specificity of only about 50 percent and a systematic review that found evidence lacking on whether fever and facial or dental pain distinguish ABRS from viral disease. That 2014 review, in adults suspected of acute bacterial rhinosinusitis, included one study and reported an odds ratio for fever of 1.02, 95 percent confidence interval 0.52 to 2.00.
The January 2025 rapid evidence review in American Family Physician nonetheless lists fever greater than 102°F (39°C) among the cardinal features of acute bacterial rhinosinusitis. As AAO-HNS summarizes the Infectious Diseases Society of America (IDSA) guideline, a high fever with purulent discharge or facial pain lasting at least three to four consecutive days at the start of illness marks a severe presentation worth considering. Reporting a temperature is useful; treating any one position as settled is not.
The 10-day threshold and the double worsening pattern
Two numbers circulate, both from the same clinical practice guideline, measured from different events. The 10-day criterion asks which direction your symptoms are moving. The watchful-waiting clock starts only once a presumed diagnosis exists.
The improvement the 10-day criterion refers to
The guideline directs a clinician to diagnose ABRS when signs of acute rhinosinusitis persist without evidence of improvement for at least 10 days beyond the onset of upper respiratory symptoms, or when they worsen within 10 days after an initial improvement, the pattern named double worsening. Symptoms still easing on day 10 are a different observation from symptoms that have stalled.
The authors replaced an earlier version that asked only whether symptoms were present 10 days or more beyond onset, because viral rhinosinusitis symptoms may persist longer than 10 days while gradually decreasing in severity. CDC’s page on sinus infection carries the same qualifier, describing symptoms lasting more than 10 days without getting better.
Ten days runs from the onset of upper respiratory symptoms and produces a presumed diagnosis. Seven days runs from that diagnosis, marking when AAO-HNS directs a clinician to start antibiotics if the illness has not improved, or earlier if it worsens at any time. Neither number describes the other.
AAO-HNS lists two alternative presentations and recorded a vote of one member in favor to nine against adding a severe pattern that the IDSA and American Academy of Pediatrics guidelines include. The double worsening sinus infection pattern is a guideline-endorsed criterion in all of them and worth describing to a clinician. How well it works as a discriminator is a separate question.
The accuracy the studies actually measured
A 2019 systematic review with bivariate meta-analysis in Annals of Family Medicine pooled the accuracy of individual signs and symptoms in outpatients with clinically suspected acute rhinosinusitis. Double sickening appeared in three of its studies and pooled at a positive likelihood ratio of 1.30, 95 percent confidence interval 0.77 to 2.40. That interval crosses 1.0, and the authors note that a likelihood ratio near 1.0 means the test adds little diagnostic information. It did not reach the review’s bacterial table, which required at least three studies per entry.
Three findings did shift the odds significantly for acute bacterial rhinosinusitis: the overall clinical impression, cacosmia (a fetid odor of the breath) and pain in the teeth. The overall clinical impression carried a positive likelihood ratio of 3.9, 95 percent confidence interval 2.4 to 5.9, while other individual signs and symptoms sat between 0.5 and 2.0. The best-performing input is the one you cannot generate alone, which is what a physician’s attention to small findings adds.
The 2016 review names four signs that, when present, significantly increase the likelihood of a bacterial cause: double sickening, purulent rhinorrhea, an erythrocyte sedimentation rate above 10 mm per hour and purulent secretion in the nasal cavity. At least three together reach a specificity of 81 percent and a sensitivity of 66 percent. One is an examination finding and one a blood test, so you can supply at most two.
Among patients with clinically suspected acute rhinosinusitis, only about one third have the bacterial form. Both sets of authors concede the limits: AAO-HNS states there is no high-level evidence showing that symptom duration and purulent discharge can reliably distinguish presumed bacteria from viral acute rhinosinusitis, and the 2025 review grades its own antibiotic-reservation recommendation level C, on expert opinion and limited studies.
The antibiotic question, as the guidelines answer it
Viruses cause most sinus infections, CDC states, and most get better on their own without antibiotics. That base rate frames the question of whether you need antibiotics for a sinus infection.
AAO-HNS directs clinicians to either offer watchful waiting without antibiotics or prescribe initial antibiotic therapy for adults with uncomplicated ABRS, and its 2015 update extended that offer to patients regardless of illness severity.
Conditions come attached: watchful waiting is offered only where there is assurance of follow-up, such that antibiotic therapy starts if the patient’s condition fails to improve by seven days after ABRS diagnosis or worsens at any time. The named exceptions are complicated sinusitis, immune deficiency and coexisting bacterial illness, and the guideline asks clinicians to weigh age, general health, cardiopulmonary status and comorbid conditions, one reason managing more than one chronic condition matters.
CDC puts it plainly: a provider may suggest watching and waiting two to three days, or write a prescription with instructions to wait that long before filling it, a safety-net or delayed prescription. Those days are CDC’s, not the guideline’s seven.
In a 2018 Cochrane review of randomized trials of antibiotics for acute rhinosinusitis in adults, 46 percent of participants, whether or not radiography confirmed the diagnosis, were cured after one week without antibiotics and 64 percent after 14 days. Its numbers needed to treat differ by route: 19 with a clinical diagnosis, 10 with radiographic confirmation, and four when computed tomography showed a sinus fluid level or total opacification. The number needed to treat for one additional harmful outcome was eight. The 2025 review expresses the same trade-off in one line: for every 100 adults treated with antibiotics, five benefit and 12 are harmed.
The two sources read that balance differently. The Cochrane reviewers concluded there is no place for antibiotics for people with uncomplicated acute rhinosinusitis, while stating they could draw no conclusions about children, people with suppressed immune systems or severe sinusitis, since the trials excluded them. AAO-HNS still frames watchful waiting and initial antibiotics as two acceptable initial approaches. Blue Point’s primary care services include the visit where that conversation happens.
Imaging, and the guideline position on it
AAO-HNS says clinicians should not obtain radiographic imaging for patients who meet diagnostic criteria for acute rhinosinusitis unless a complication or an alternative diagnosis is suspected. The 2025 review rates the parallel recommendation, that imaging not be used routinely to distinguish viral from bacterial disease, at evidence level B. StatPearls gives the reason: computed tomography (CT) has poor specificity in acute sinusitis, because nearly 50 percent of asymptomatic patients and almost 90 percent of those with an upper respiratory tract infection may show sinus air-fluid levels on the scan.
Dust, fall allergens, and the local overlay
The Las Vegas planning area is a federally designated PM-10 maintenance area with a Serious classification, redesignated from nonattainment, in an EPA Green Book report current as of August 31, 2026. Coarse particulate matter is not pollen, and on pollen the national picture holds: US patients with allergic rhinitis are commonly sensitized to grass, dust mites and ragweed.
Symptom sets coincide, and acute bacterial sinusitis is, in StatPearls’ words, likely underreported by patients and overdiagnosed and overtreated by clinicians. Blue Point’s guides to fall allergy triggers in Las Vegas and air quality and monsoon dust cover the local version of each. A separate guide to asthma and COPD flares takes up wheeze or chest tightness.
The threshold for a visit, and what same-day access is for
CDC writes its own list for patients deciding when to see a doctor for sinus congestion: severe symptoms such as severe headache or facial pain, symptoms that get worse after improving, symptoms lasting more than 10 days without getting better, fever longer than three to four days, and multiple sinus infections in the past year. Blue Point’s guide to symptoms that deserve evaluation takes a wider view.
Serious complications are uncommon. AAO-HNS directs clinicians to examine for orbital or intracranial spread of infection in patients with a reconfirmed ABRS diagnosis who fail treatment, findings scoped to that group rather than a general checklist. StatPearls puts complications at approximately one in every 1,000 cases, and the 2025 review cites a Dutch study in which severe complications requiring hospitalization occurred in one in 32,000 adults.
The conservative path depends on access. Watchful waiting requires assured follow-up, so a physician who can see you within a few days is a condition of the strategy rather than a convenience. Blue Point’s walk-through of a same-day appointment covers that visit, and its comparison of primary care and urgent care addresses where a first stop belongs.
Frequently Asked Questions
When do recurrent sinus infections become chronic sinusitis?
StatPearls describes the recurrent pattern as four episodes lasting less than four weeks with complete symptom resolution between them, while chronic rhinosinusitis refers to symptoms that persist for more than 12 weeks.
These are separate clinical patterns rather than different degrees of the same condition. Repeated episodes with symptom-free periods are evaluated differently from congestion and sinus symptoms that never fully resolve.
When should I see an ear, nose and throat specialist for sinus problems?
Referral to an otolaryngologist, or ENT specialist, is typically unnecessary for uncomplicated acute sinusitis because most cases are viral and improve without specialty treatment.
Referral or additional imaging may become appropriate when someone has recurrent rhinosinusitis, persistent symptoms, concern for complications, or another diagnosis that needs to be considered.
Can allergies make sinus infections more likely?
Yes. Allergic rhinitis appears among the mucosal edema factors that can predispose someone to acute rhinosinusitis, and CDC lists seasonal allergies among the risk factors for sinus infection.
The relationship is not absolute, however. Allergies can contribute to congestion and inflammation, but having allergic rhinitis does not automatically mean a sinus infection is bacterial or that treatment should be different.
Conclusion
Distinguishing a sinus infection from allergies or a cold is rarely as simple as checking the color of nasal drainage or counting how many days congestion has lasted. The overall pattern matters more: whether symptoms are improving, staying the same, worsening after initially getting better, or occurring alongside features such as facial pain, fever, itching, or repeated episodes.
Most acute sinus symptoms are caused by viruses and improve without antibiotics. When symptoms persist more than 10 days without improvement, worsen after initially getting better, or become severe, a medical evaluation can help determine whether the pattern fits bacterial sinusitis, allergies, another cause of congestion, or a condition requiring different treatment.
If your congestion, facial pressure, or sinus symptoms are not improving, contact Blue Point Medical Group to schedule an appointment. Our primary care team can evaluate the pattern of your symptoms, review possible causes, and help determine whether watchful waiting, symptom management, or additional treatment may be appropriate.
This article is for informational purposes only and does not constitute medical advice. Always consult your physician or a qualified healthcare provider for questions about your health or before making changes to your treatment plan.
