Sneezing, runny nose, congestion, tiredness and a scratchy throat appear in all three. And they can coexist — having hay fever does not protect you from a virus.
Some features do discriminate reasonably well.
Points to Hay Fever
- Itching — of the nose, eyes, throat or roof of the mouth. Viruses rarely cause this, and it is the single most useful discriminator.
- Sneezing in runs of several at a time
- Clear, watery discharge rather than thick or coloured
- No fever
- Symptoms tracking the environment — worse outdoors, on dry windy days, after mowing, better indoors or in rain
- Duration in weeks, following a seasonal pattern year on year
- Symmetrical, itchy eyes
Points to a Cold
- Gradual onset over a day or two, then improvement within about a week
- Discharge that changes — clear at first, thicker and coloured later
- Sore throat and cough more prominent
- Mild aches, sometimes a slight temperature
- No itching
- Someone around you had the same thing last week
Points to Covid or Flu
- Fever — hay fever does not cause one
- Significant muscle aches and marked fatigue
- Loss or change of taste or smell, though congestion from any cause can dull smell
- Breathlessness, which needs assessment
- Faster onset, and a course of days rather than weeks
If you are unsure and it matters — you are around vulnerable people, or you work in healthcare — test rather than reason it out.
The Practical Test
If you already have hay fever and are already taking an antihistamine, the useful question is whether this feels like your usual hay fever. A hay fever sufferer generally knows their own pattern, and a symptom set that breaks it — fever, aches, symptoms that ignore the weather — is a reason to consider something else.
Equally, an antihistamine that suddenly does nothing at all may be a clue that what you have is not the thing it treats.
The Asthma Overlap
Poorly controlled hay fever worsens asthma. Wheezing, chest tightness, a persistent cough or breathlessness during pollen season should be taken seriously and reviewed, not written off as a bad hay fever year.
This works both ways: getting hay fever properly controlled often improves asthma control, which is a reason to treat it thoroughly rather than tolerate it.
When to Get Advice
- A fever that does not settle
- Breathlessness or wheeze
- Symptoms lasting more than about ten days and getting worse rather than better
- Facial pain or pressure, suggesting sinusitis
- Symptoms in one nostril only, or blood-stained discharge
- Hay fever not controlled by over-the-counter treatment used properly
The Cheap Insurance
If you know you get hay fever, having a non-sedating antihistamine and a steroid nasal spray in the house before the season starts costs very little — own-brand cetirizine or loratadine is among the cheapest medicine you can buy. It also means that when symptoms appear you are testing a known quantity, which makes it much easier to tell whether something else is going on.