Sputum is mucus produced in the lower airways, such as the lungs and bronchi. When this substance becomes purulent, it means it contains pus composed of dead white blood cells. These cells are the remnants of the body’s immune response, signaling an active infection or significant inflammation deep within the respiratory tract.
Identifying Purulent Sputum
Purulent sputum is identified by its distinct color and consistency. It appears opaque and may be yellow or green. This coloration is a direct result of enzymes released by white blood cells during an inflammatory response to combat infection.
The texture is also a key characteristic. It is often thick and sticky compared to healthy mucus, which is clear and watery. This change in consistency is due to the high concentration of cellular debris from the immune battle, which can make it more difficult to cough up.
Underlying Medical Conditions
The production of purulent sputum is most often linked to bacterial respiratory infections. Acute bronchitis, an inflammation of the bronchial tubes, can progress from a dry cough to one that produces purulent material. Bacterial pneumonia causes the air sacs in the lungs to fill with pus and fluid, leading to a cough that expels thick, colored sputum.
Chronic conditions can also be a cause, particularly during periods of exacerbation. People with chronic obstructive pulmonary disease (COPD) may experience flare-ups, often triggered by a secondary infection, that result in increased and purulent mucus production. Another condition, bronchiectasis, involves permanent damage to the airways, which allows mucus and bacteria to pool, making recurrent infections and the chronic production of purulent sputum a common feature.
When to Consult a Healthcare Provider
While producing purulent sputum warrants attention, certain symptoms signal the need for a prompt medical evaluation. A high fever reaching 102°F (39°C) or higher can indicate a significant infection. Difficulty breathing, shortness of breath, or chest pain that worsens when you breathe or cough are also serious signs.
You should also consult a provider if the sputum appears rust-colored or is streaked with blood. If symptoms, including the productive cough, persist for more than a week without improvement, medical advice is recommended. This is particularly important for individuals with pre-existing lung conditions or weakened immune systems.