By Dr Chun Tang — MBChB (Manchester), MRCGP, MBA · Practising NHS & Private GP · Founder, Little Ox

Dr Tang in the Press: How to Tell if It's Hay Fever or a Cold — A GP's Guide

In April 2025 I was interviewed by The Portugal News and several other publications about one of the most common questions I get every spring: how do you know whether your sneezing and runny nose is hay fever or a cold? With pollen season starting earlier each year due to changing climate patterns, it's a genuinely useful distinction — because the treatment is completely different.

What I Said in the Press

The key differences I outlined:

Cause: A cold is caused by a virus — usually rhinovirus — that spreads through coughs, sneezes and contaminated surfaces. Hay fever is an allergic reaction to airborne allergens: pollen, dust mites, pet dander. No virus involved.

Symptoms: Both can cause a runny nose and sneezing. But hay fever characteristically causes itchy eyes, itchy throat and watery eyes — symptoms you don't typically get with a cold. A cold, on the other hand, commonly causes a sore throat, cough and sometimes a low-grade fever. Hay fever doesn't cause fever.

Onset: Hay fever can come on suddenly when pollen levels spike. A cold builds gradually over a few days.

Duration: A cold typically resolves in 7–14 days as your immune system clears the virus. Hay fever can persist for weeks or months throughout pollen season.

Treatment: Hay fever responds to antihistamines, nasal corticosteroid sprays and allergen avoidance. A cold requires symptomatic relief — paracetamol, decongestants, rest and fluids — while your immune system does the work.

The Connection to Gut Health and NAD+

Something I find clinically important but rarely discussed in these press articles: both allergic responses (like hay fever) and susceptibility to viral infections (like colds) are significantly modulated by the health of your gut microbiome and your NAD+ levels.

Approximately 70% of your immune system lives in your gut. A diverse microbiome helps regulate the Th1/Th2 immune balance — dysregulation of which is directly implicated in allergic conditions like hay fever. Patients with depleted microbiome diversity tend to have more severe and prolonged allergic responses. Supporting microbiome diversity year-round with a quality live culture like our Bio Cultures Complex is one of the most evidence-backed approaches to improving immune regulation.

NAD+ depletion, which accelerates after 40, compromises the efficiency of immune cell function across the board — affecting both your viral defence and your inflammatory regulation. NMN Pure addresses this at the cellular level, supporting the immune cells that need NAD+ to function properly.

Neither NMN nor live cultures will prevent hay fever — but maintaining robust immune regulation through these channels can meaningfully reduce how severely you're affected by seasonal immune challenges.

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