Coughing up clear phlegm: What does it mean?

Overview

Clear phlegm usually means your body is clearing out irritants or fighting a mild infection like a cold. In Australia, it’s often linked to hay fever, allergies, bushfire smoke, or reflux. While mostly harmless, persistent coughing with clear phlegm may sometimes indicate conditions like asthma, post-nasal drip, or gastro-oesophageal reflux (GORD). Phlegm is the sticky mucus produced in your lungs and airways. It helps trap dust, allergens, and germs so your body can remove them. Its colour can reveal information about your health—clear, green, yellow, or even blood-tinged. Clear phlegm is generally harmless, but can occasionally suggest an underlying problem. Let's explore what clear phlegm means, the reasons behind it, when it might signal a problem, and the ways to manage it.

Cough with clear mucus mean

A cough with clear mucus generally suggests the body is responding to irritation or an infection in the respiratory system. It is quite common and usually not serious.

Causes of clear phlegm

• Viral infections- like a cold or early-stage flu

• Allergies or hay fever- quite prevalent in Australia

• Post-nasal drip- mucus from the nose dripping into your throat

• Irritants- such as smoke, air pollution, dust, or chemicals

• Reflux (GORD)- stomach acid irritating your throat and airways.

 

Is clear phlegm linked to hay fever or allergies in Australia?

Yes. Hay fever is one of the most common conditions in Australia, affecting nearly 30% of the population¹. During peak pollen seasons (especially spring), clear phlegm can increase due to exposure to:

• Grass, tree, or weed pollen

• Mould spores

• Pet dander

• Dust mites

If you’re sneezing, coughing up clear phlegm, with itchy eyes and a runny nose, it’s likely allergies, not an infection.

Clear phlegm vs early infection

It can be hard to figure out, but here’s a quick guide:

Symptom	Allergies/Hay Fever	Viral Infection (Cold/Flu)
Phlegm colour	Clear	Clear (early), yellow/green (later)
Sneezing	Frequent	Sometimes
Fever	Rare	common
Itchy eyes/nose	Common	Rare
Duration	Weeks (seasonal)	Days to a week

 

 Clear phlegm with bubbles means

Clear phlegm with bubbles can indicate that the body is producing mucous due to an infection, irritation, or inflammation in the respiratory tract. The bubbles might form from air trapped in the mucous as it is expelled or from the mucous mixing with air during coughing. But sometimes, it can be linked to:

Common causes:

• Post-nasal drip

• Mild viral infections

• Irritants like smoke or bushfire pollution

Less common causes (worth checking with a GP):

• Reflux (GORD)- common in Australia; stomach acid can lead to coughing and mucus production.

• Asthma- may bring clear, sticky phlegm with coughing.

• Chronic bronchitis or early COPD- more common in smokers or people exposed to dust or chemicals.

Does clear phlegm mean infection?

Not necessarily. Clear phlegm usually means your body is working hard to clear out dust, allergens, or a mild virus. But it can also be the early stages of a viral infection like a cold, flu, or COVID-19, before the mucus shifts to yellow or green. Keep an eye on symptoms that suggest it may be more than just clear phlegm:

• Fever

• Body aches

• Thick, yellow or green mucus after a few days

• Shortness of breath

How to manage

Here are some ways to calm the cough and help you get better:

Home remedies

• Stay hydrated- dilutes the mucus, helping it to move out smoothly.

• Steam inhalation- loosens congestion

• Honey and ginger tea- calms the throat

• Avoid irritants- smoke, dust, strong smells, bushfire air

• See a doctor- if the cough lasts more than 3 weeks

 

Treating the cause

• Viral illness- rest, fluids, paracetamol if needed

• Hay fever or allergies- avoid known triggers, antihistamines

• Reflux (GORD)- avoid spicy, acidic foods, elevate head at night

• Postnasal drip- decongestants, saline rinse

• Environmental triggers- use humidifiers, keep windows closed on high pollen days

Why do I cough up clear, jelly-like mucus balls?

It sounds strange, but it is not usually serious. This generally happens when mucus builds up and thickens. It can be caused by:

• Allergies

• Asthma

• Reflux

• Mild viral infections

But if you’re also wheezing, short of breath, or have chest pain, see a online GP.  

Other phlegm colours mean

Here’s a quick guide to help:

Phlegm Colour	What it could mean
Clear	Normal, allergies, early cold
White	Congestion, mild infection
Yellow	Body fighting infection (usually viral)
Green	Possible bacterial infection. See a GP if it lasts > 10 days
Brown	Smoke, pollution, old blood
Red/pink	Blood – see a GP if it happens more than once
Black	Smoke, dust, fungal infection. Needs urgent review.

 

When to go to the GP vs when to use telehealth

See a GP in person if you have:

• Cough lasting more than 3 weeks

• Chest pain

• Wheezing or shortness of breath

• Fever over 38°C

• Phlegm turning thick green, red, or black

Use telehealth if:

• You need a medical certificate

• You’re not sure whether your symptoms indicate an allergy or an infection

• You need advice on allergy or reflux medications

• Your  symptoms are mild but persistent

• You want a prescription without leaving home

Call 000 if you’re struggling to breathe or having acute chest pain.

How Hola Health can help

If you’re coughing up clear phlegm and aren’t sure whether it’s due to allergies, reflux, or a viral infection, Hola Health’s online doctors can help you get clarity and relief quickly. Through a simple telehealth appointment, you can:

• Consult an Australian GP online — discuss your symptoms and get professional advice without visiting a clinic.
• Get online prescriptions for allergy medication, reflux treatment, or cough relief when needed.
• Access medical certificates online if your cough is affecting work or study.
• Get personalised treatment plans and follow-up support for ongoing conditions like asthma, GORD, or chronic allergies.

Hola Health provides fast, secure, and convenient telehealth care — so you can recover comfortably from home. Book a telehealth appointment with Hola Health and get expert care from an Aussie GP in minutes.

Conclusion

Clear phlegm is usually nothing to worry about. It’s often associated with mild infections, allergies, or irritants in the air. But if your cough is persistent or comes with worrying symptoms, don’t ignore it. Book a telehealth appointment with Hola Health today and speak to an Australian GP and get peace of mind fast.