WHAT DO GREEN, YELLOW, AND BROWN PHLEGM MEAN

Phlegm is a thick form of mucus produced in the lungs to trap and clear out irritants and germs. Its amount usually increases when your body is fighting an illness, such as a cold or an allergy flare-up.

The appearance and texture of phlegm can vary depending on the trigger. It may be sticky, foamy, or dense, each indicating possible causes such as infections or lung conditions.

While usually, phlegm is clear, light, and barely noticeable, during a cold or infection, it often thickens and changes color. Different health issues can also affect the appearance of phlegm.

Phlegm color changes are not random; they can indicate underlying respiratory issues. Read on to learn what the color means, possible causes, and when to seek treatment.

What do different phlegm colors mean

1. Green phlegm

Green or dark green phlegm usually shows that your body is fighting an infection, whether viral or bacterial. The green color comes from white blood cells, especially neutrophils, which are active at the infection site. It’s common in illnesses like bronchitis, sinusitis, or pneumonia.

As these immune cells respond, they release enzymes that turn the mucus green. The longer or more severe the infection, the darker the phlegm becomes. This color change shows the activity and buildup of these infection-fighting cells.

2. Yellow phlegm

Yellow phlegm usually signals that your body is fighting a mild infection, such as a common cold or an early-stage respiratory illness. The yellow color results from dead white blood cells that have responded to the infection. In some cases, it may also be linked to conditions like bronchitis or pneumonia.

When viruses, allergens, or irritants enter your body, the immune system responds by releasing enzymes and producing more mucus. This reaction causes the phlegm to turn yellow and can also result from inflammation, allergies, or thick mucus buildup.

3. Brown Phlegm

Brown phlegm often indicates the presence of old blood, chronic inflammation, or exposure to irritants like smoke or dust. The brownish tint generally forms when blood stays in the airways and oxidizes. It's also common in people with long-term respiratory conditions such as bronchitis, COPD, or cystic fibrosis.

When your lungs are irritated by pollution, smoking, or infection, the body produces extra mucus as a protective response. If minor bleeding occurs in the airways, the dried blood mixes with mucus, causing it to turn brown over time. This is especially common in persistent or recurring respiratory infections.

Treatment

If you’re dealing with thick mucus and chest congestion from a common cold, staying hydrated by drinking warm water or herbal teas, and getting plenty of rest, such as taking naps or going to bed early, can help your body recover faster.

For effective relief without a prescription, choose a mucus-thinning medicine, such as Mucinex or Mucinex^® Chest Congestion Guaifenesin 600 mg Tablets^*, which helps thin and loosen stubborn phlegm, making coughs more productive.

This bi-layer tablet dissolves quickly and releases medicine for 12 hours. Mucinex^® is indicated for adults and children 12 years and older.

^*Always read and follow the complete product label for specific dosing instructions, as this product may not be right for everyone.

FAQs

How can you tell if phlegm is from allergies or an infection?

The color and consistency of phlegm can help distinguish between an infection and allergies. Clear or light-colored phlegm typically indicates allergies or mild infections, whereas thick, white, yellow, or green phlegm often suggests a viral or bacterial infection.

Does green phlegm always mean you need antibiotics?

Green phlegm doesn’t always mean you need antibiotics for a bacterial infection. While green or yellow phlegm can indicate infection, it is often caused by a viral illness that resolves on its own.

What foods or drinks can help reduce phlegm in the throat?

To reduce phlegm in the throat, drink warm fluids such as tea or lemon water with honey to thin the mucus. Stay well-hydrated with water and herbal teas. Foods like ginger, garlic, and certain fruits and vegetables may also help ease inflammation and mucus buildup.