Is it a cold or an allergy? How to tell the difference

It starts with a sniffle, a sneeze, maybe a bit of a cough. But what’s causing it — is it just a common cold, or could it be allergies? While the symptoms can be similar, the cause (and the treatment) is very different.

At MedEx, we often see patients wondering whether they need rest and fluids or an antihistamine — and whether testing is worth it. In this blog, we’ll help you figure it out.

Understanding the Basics

The Common Cold:

• Cause: Viral infection (like rhinovirus)
• Contagious: Yes
• Duration: 7–10 days
• Season: More common during the rainy season or cooler months in Thailand

Allergies:

• Cause: Immune system reaction to allergens (e.g. pollen, dust mites, mold, pet dander)
• Contagious: No
• Duration: Can last weeks or months, depending on exposure
• Season: Often triggered during hot, dry seasons or when pollution and pollen levels are high

Key Signs to Help You Decide

Think About Timing

• Did your symptoms start suddenly after being outside or in a dusty room? Likely allergies.
• Have others around you caught the same thing? Probably a cold.
• Is it the dry season and your eyes won’t stop itching? That points to allergies.
• Are your symptoms easing after a few days? Colds tend to run their course faster.

When to Consider a Test

Sometimes, it’s hard to tell based on symptoms alone. That’s where medical tests can help.

1. Allergy Testing

• What it does: Identifies specific allergens triggering your symptoms
• Types:
  • Skin Prick Test: Small amounts of allergens are placed on your skin
  • Blood Test (IgE test): Measures immune response to allergens
• Who it’s for: People with recurrent, seasonal, or persistent symptoms

2. Viral Panel or Nasal Swab Test

• What it does: Detects common cold or flu viruses
• Who it’s for: Those with acute symptoms, especially if fever is present or COVID-19 is suspected

At MedEx, we offer a wide range of lab tests across Thailand, and our medical team can guide you to the right one based on your symptoms.

What to Do Next

If you’re still unsure, don’t guess — consult a doctor. Knowing the root cause of your symptoms means you can treat them properly, avoid unnecessary medication, and feel better faster.

You can also book allergy or viral testing with us, quickly and conveniently, anywhere in Thailand.