Nose and sinus No. 05
Allergy, cold or sinusitis: what is the difference?
A blocked nose is a description, not a diagnosis. Sneezing and itchy eyes behave like allergy. A sore throat, ache and a short course behave like a viral cold. Facial pressure that lasts past ten days, or improves and then worsens, is when sinusitis deserves a proper look. Most sinus infections are still viral.
Not every blocked nose is a sinus infection. Treating them all the same is how people take the wrong medicine.
On this page
In short
- Sneezing, itchy eyes and a watery nose behave like allergy.
- A sore throat, aches and a short course behave like a viral cold.
- Facial pressure that lasts past ten days, or gets better and then worse, needs a closer look.
- Most acute sinus infections are viral. Green mucus is not a reason for antibiotics.
- Swelling around an eye, or a severe headache with fever, is urgent.
The word “sinus” has been stretched until it means any stuffy face. Allergy, a cold, and sinusitis overlap in the mirror. They do not overlap in the treatment. One is a trigger. One is a virus that leaves. One is inflammation in the sinus cavities, usually still viral, sometimes bacterial, sometimes a longer pattern. Naming it correctly is the whole skill.
| What you notice | Allergy | Viral cold | Sinusitis |
|---|---|---|---|
| Often begins | Soon after dust, pollen, smoke or a pet | Over a day or two | During a cold, or when a cold stalls |
| Nose | Sneezing, watery, usually both sides | Blocked, with a sore throat | Blocked, with drip backward |
| Eyes | Itchy and watery | Rarely the main feature | Pressure more than itch |
| Body | No fever, no ache | Fever and aches are common | A low fever is possible |
| Face | Itch, not pressure | General congestion | Pressure over cheeks, eyes or forehead |
| Course | Lasts while the trigger lasts | Usually easing within a week to ten days | Still there after ten days, or better and then worse |
What an allergy usually feels like
Repeated sneezing, itchy eyes, a watery nose, and a clear sense that a room or a season did this: that pattern is allergic rhinitis until a doctor says otherwise. It can arrive in minutes. It does not bring a fever. It lasts as long as the trigger, which in Mumbai may be dust and mites more faithfully than a pollen calendar. Smoke, including festival smoke, can mimic it or pile on top of it. The longer account is allergic rhinitis.
A steroid spray used for four days has not had a trial. The same spray used properly for several weeks is information. That distinction is why a nose and sinus consultation asks about weeks, not about the bottle you bought yesterday.
What a viral cold usually feels like
A cold builds. The throat is sore, the nose blocks, the body aches, there may be a fever, and then, inconveniently, it leaves. Most people are turning the corner within a week to ten days. Cough can outlast the rest, which is discussed in the guide to a child’s night cough and is just as true for adults. Antibiotics do not speed a virus.
When it starts to look like sinusitis
The sinuses are air spaces in the cheeks, between the eyes, and in the forehead. Their drainage holes are narrow. When the lining swells, mucus sits, pressure builds, and the face hurts in a place you can point to. Dentists hear about the cheek. The forehead gets blamed on screens.
Acute sinusitis often is the cold, still in the sinuses. Seek an opinion if symptoms are severe, if they are still not improving after about ten days, or if they improved and then worsened. That second worsening is the clue people miss. Chronic symptoms, lasting twelve weeks, are a different conversation, about inflammation, allergy, and sometimes the shape of the nose. The condition page for sinusitis goes further.
Why sinusitis does not automatically mean antibiotics
Most acute sinusitis is viral. The American Academy of Allergy, Asthma and Immunology and the CDC both make the same point in public advice: antibiotics do not help a virus, and most people get better without them. Green mucus is not a bacterial badge. A doctor may still prescribe an antibiotic when the story is long, severe, or worsening in the pattern above, or when someone is unwell in a way this page cannot judge. Taking one “for the sinus” before that judgement is how side effects arrive without a benefit.
Saline rinses, rest, and fluids help the viral majority. Sprays have a right dose and a wrong one. Decongestant sprays used for many days in a row can block the nose they were meant to open. If you are on day ten of a bottle, say so at the visit.
What an ENT visit sorts out
The examination looks at the lining, the septum, and whether mucus is trapped. Allergy, a leftover virus, and a nose that cannot physically drain are three different plans. Nose and sinus care at the clinic is that conversation. Fever with swelling of the eye or forehead, a severe headache, a stiff neck, or confusion is not a clinic-form problem. That is emergency care.
People also ask
The questions that follow this one.
How can I tell an allergy from a cold?
Allergy tends to start soon after a trigger and brings sneezing, itchy watery eyes and a watery nose, without fever or body ache. A cold builds over a day or two, often with sore throat, ache and sometimes fever, and then eases over a week to ten days. Itch points to allergy. Ache points to a virus.
How do I know if a cold has become sinusitis?
Facial pressure or pain, congestion that is not improving after about ten days, or symptoms that get better and then worse again, are reasons to have sinusitis considered. A stuffy nose on day three of a cold is usually still the cold.
Does green or yellow mucus mean I need antibiotics?
No. Mucus often changes colour during a viral cold. Most acute sinus infections are viral, and antibiotics do not treat viruses. A clinician may consider antibiotics if symptoms are severe, last beyond ten days without improvement, or worsen after improving.
How long does acute sinusitis last?
Many episodes settle over one to two weeks, because they are viral. Symptoms still going after ten days, or a second worsening, should be assessed. Symptoms that continue for twelve weeks are called chronic and need a different plan.
Can allergies lead to a sinus infection?
They can contribute. Swollen allergic lining blocks the small drainage openings, so mucus sits. Controlling the allergy, often with a proper trial of a nasal steroid rather than a few days of spray, reduces that setup. It does not mean every allergic sneeze is sinusitis.
What is the difference between a sinus headache and a migraine?
Sinus pressure is usually accompanied by a blocked nose or drip, and it sits over the cheeks, between the eyes or on the forehead. Many headaches called sinus headaches are migraine. An examination is how those are separated, especially if the nose looks calm while the head does not.
When should I see an ENT for sinus symptoms?
If symptoms pass ten days without improvement, if they worsen after getting better, if you have repeated episodes, or if one side of the nose stays blocked. Eye swelling, a severe headache, or difficulty breathing should not wait for an appointment.
Sources
- American Academy of Allergy, Asthma and Immunology: colds, allergies and sinusitis
- CDC: sinus infection basics, including when antibiotics are not needed
- Mayo Clinic: acute sinusitis usually follows a cold and often needs no antibiotic
Guidance changes. This page was drafted on 6 November 2026 and is not a record of your examination. For a sudden change, or any trouble breathing, do not wait on an article.