Phlegm Color Chart
The Phlegm Color Chart is a health reference tool covering phlegm color chart, mucus color chart, what does phlegm color mean, green phlegm meaning. Use the chart below to look up values instantly. Printable and downloadable versions are available on this page.
Symptom Color Checker
Select your phlegm color and any accompanying symptoms to get likely conditions, urgency level, and whether to seek medical care.
Phlegm Color Chart — What Each Colour Means
| Phlegm Colour | Most Likely Cause | Possible Medical Cause | Urgency Level | What to Do |
|---|---|---|---|---|
| Clear or White | Normal healthy mucus production | Mild viral infection or allergies — clear mucus with cold symptoms is typical of viral URI | Normal to Monitor | Stay hydrated. Rest. Over-the-counter saline rinse can help clear passages. |
| White and Thick or Frothy | Congestion from cold or allergies | Possible early respiratory infection | Monitor | Increase fluids. If persisting more than 10 days see a doctor. |
| Yellow | Immune system response — white blood cells fighting infection | Viral URI (common cold) progressing normally — yellow does not always mean bacterial | Monitor | Yellow phlegm alone does not require antibiotics. See doctor if symptoms worsen or last more than 10 to 14 days. |
| Green | Active infection — heavier concentration of dead neutrophils | Bacterial sinusitis, bacterial bronchitis, pneumonia | See doctor if persisting more than 7 to 10 days | Persistent green phlegm for over a week with fever warrants medical evaluation. |
| Brown or Rust | Old blood mixed with mucus — may indicate prior bleeding that has oxidised | Chronic bronchitis, lung abscess, old blood from coughing hard | See doctor if not explained by recent cough injury | Brown rust-coloured phlegm with no obvious cause should be evaluated. |
| Red or Pink | Fresh blood — active bleeding in the respiratory tract | Bronchitis, pneumonia with bleeding, pulmonary embolism (pink frothy), tuberculosis | See doctor promptly — emergency if large amount | Blood in sputum (haemoptysis) always warrants medical evaluation. Pink frothy sputum is a medical emergency. |
| Black | Environmental exposure — heavy smokers or coal miners | Fungal infection (Aspergillus niger) — very rare | See doctor | Seek evaluation especially if you do not smoke or have occupational exposure. |
| Grey | Air pollution or dust exposure | Possible fungal infection in heavy smokers | Monitor | Usually environmental. If accompanied by respiratory symptoms see a doctor. |
| Foamy or Frothy — Pink | Pulmonary oedema (fluid in lungs) | Congestive heart failure — emergency | Emergency — call 911 | Pink frothy sputum is a medical emergency indicating fluid in the lungs. |
Source: American Lung Association and NHS respiratory guidelines
Phlegm vs Mucus — What Is the Difference?
- Mucus — the thin, slippery fluid produced continuously by mucous membranes throughout the body including the nose, sinuses, throat, lungs, and digestive tract. Normal daily mucus production is approximately 1 to 1.5 litres.
- Phlegm — a specific term for mucus produced in the lower respiratory tract (lungs and bronchi) that is coughed up. Not all mucus is phlegm — only mucus from the chest that is expectorated.
- Sputum — a clinical term that includes phlegm plus any saliva or other material that is expectorated. Sputum can be sent to a laboratory for culture and sensitivity testing to identify bacteria.
- Post-nasal drip — mucus from the upper respiratory tract (nose and sinuses) draining down the back of the throat. This is the most common cause of chronic cough and is not technically phlegm even though it is commonly confused with it.
When to See a Doctor
Seek immediate emergency care if you cough up pink frothy sputum — this indicates fluid in the lungs and is a medical emergency.
- Any blood in phlegm (red, rust, or pink) not explained by a minor cough injury — see a doctor within 24 hours.
- Green phlegm persisting for more than 7 to 10 days accompanied by fever or facial pain — may indicate a bacterial infection requiring antibiotics.
- Any phlegm with chest pain, shortness of breath, or high fever (above 103°F) — seek same-day medical care.
- Brown or black phlegm in a non-smoker with no obvious environmental exposure.
- Persistent cough with phlegm lasting more than 3 weeks — warrants evaluation to rule out pneumonia, bronchitis, or other conditions.
Symptom Color Checker
Select your phlegm or mucus color and any accompanying symptoms to get likely conditions, urgency level, and whether to seek medical care.
Frequently Asked Questions
Yellow phlegm means your immune system is actively fighting an infection — white blood cells called neutrophils give mucus its yellow colour as they battle viruses or bacteria. Yellow phlegm alone does not indicate a bacterial infection requiring antibiotics.
Not necessarily — green phlegm can occur in both viral and bacterial infections. Most respiratory infections are viral and resolve without antibiotics. See a doctor if green phlegm persists for more than 7 to 10 days or is accompanied by high fever and facial pain.
Brown or rust-coloured phlegm usually contains old blood — oxidised blood from previous coughing or bleeding turns brown. Heavy smokers may also produce brown phlegm from tar deposits. Persistent unexplained brown phlegm should be evaluated by a doctor.
Coughing up small amounts of blood (streaks in mucus) after intense coughing can result from minor airway irritation and may not be serious. However any significant amount of blood in phlegm, recurring blood, or pink frothy sputum requires prompt medical evaluation.
Clear phlegm is normal healthy mucus. During an early viral cold clear phlegm is typical — it becomes yellow or green as the immune response intensifies later in the illness.
Stay well hydrated — 8 or more glasses of water daily helps thin mucus making it easier to clear. Steam inhalation, saline nasal rinses, a humidifier, and avoiding dairy products (which thicken mucus for some people) can also reduce congestion.
Colour alone is not a reliable indicator of severity. Green phlegm can occur in mild viral infections while clear phlegm can occur in serious asthma or early pneumonia. The combination of phlegm colour with other symptoms (fever, chest pain, duration) provides more meaningful clinical information.
A wet or productive cough produces phlegm or mucus that is brought up from the airways. A dry cough produces no phlegm and is typically triggered by irritation, allergies, post-nasal drip, or a viral infection that has not yet progressed to the productive stage.