Allergy vs. Cold vs. Sinusitis: How to Tell the Difference (8 Questions Answered)
A blocked, runny nose is the single most common reason patients aren’t sure whether to wait it out, take an antihistamine, or see a doctor — because a cold, allergic rhinitis, and sinusitis can look almost identical on day one. Here are direct answers to the questions asked most often, in clinic and online.
Q1. What’s the basic difference between the three?
A cold is a short viral infection that resolves on its own; allergic rhinitis is an ongoing immune reaction to a trigger like dust or pollen; sinusitis is inflammation of the sinuses, often following a cold, that can become bacterial if it persists. They’re related, not separate boxes — a cold can trigger sinusitis, and untreated allergic rhinitis makes both colds and sinusitis more frequent by keeping the nasal lining chronically inflamed and the sinuses poorly drained.
Q2. How long should each one actually last?
A cold typically resolves within 7–10 days. Allergic rhinitis lasts as long as you’re exposed to the trigger — which can mean daily symptoms for months. Acute sinusitis can run up to 4 weeks; beyond 12 weeks, it’s considered chronic. Duration is one of the most useful clues you have: symptoms still going strong after 10 days are unlikely to be “just a cold.”
Q3. Does the colour of nasal discharge tell you what it is?
Not reliably — this is one of the most persistent myths in nasal illness. Yellow or green discharge is common in both ordinary viral colds and bacterial sinusitis, and doesn’t by itself mean you need antibiotics. Discharge often turns darker in the middle of an ordinary cold as the body’s immune cells do their work, then clears again. Colour alone is a poor guide — duration, fever, and facial pain are far more useful.
Q4. Does having a fever help distinguish between them?
Allergic rhinitis does not cause fever — if there’s a fever, it isn’t allergy alone. A cold can cause a mild, low-grade fever; sinusitis, especially if bacterial, is more likely to cause a persistent or higher fever. Fever is one of the more useful differentiators precisely because allergy is ruled out immediately if it’s present.
Q5. Itchy eyes, throat, and constant sneezing — what does that pattern usually mean?
Itching — of the eyes, nose, throat, or roof of the mouth — combined with bouts of sneezing is a strong pattern for allergic rhinitis rather than a cold or sinusitis. Colds and sinusitis rarely cause significant itching. If symptoms also show a pattern — worse at a particular time of day, season, or in a particular room (like on waking, suggesting dust mite exposure) — that further supports an allergic trigger over an infection.
Q6. What does facial pain or pressure usually point to?
Pressure or pain over the cheeks, forehead, or around the eyes — especially if it worsens when bending forward — points more towards sinusitis than a simple cold or allergy. This happens because inflamed, blocked sinuses build up pressure. Isolated facial pain without significant nasal symptoms is less typical and worth a specific examination rather than self-treatment.
Q7. Can I have allergy and sinusitis at the same time?
Yes, and it’s more common than people realise — chronic, poorly controlled allergic rhinitis is one of the main reasons some people get sinus infections repeatedly. Allergic inflammation blocks the small drainage channels of the sinuses, creating conditions where bacteria can take hold after what starts as a simple cold. This is why treating the underlying allergy properly often reduces how often sinus infections happen, not just the day-to-day nasal symptoms.
Q8. When should I stop guessing and see a doctor?
See a doctor if symptoms persist beyond 10 days without improving, keep recurring, involve one-sided facial pain, come with a high or persistent fever, or simply aren’t responding to over-the-counter treatment. A proper nasal examination — and, where relevant, allergy testing — replaces guesswork with an actual answer, and directs treatment at the right target instead of cycling through medications for the wrong condition.
Dr Pranshu Mehta is a DLO ENT Surgeon and Allergy Specialist at Rog Nidan ENT & Dental Clinic, C-2/275 Janakpuri, New Delhi. Not sure which one you have? WhatsApp +91 98186 35660. Related: Allergic Rhinitis — Full Guide | Chronic Sinusitis Guide | Skin Prick Test (SPT) | Take the Symptom Checker. Watch: @TheENTSurgeons on YouTube.