Sputum Color in Pneumonia: What Green, Yellow, and White Mean

Sputum is the secretion of the respiratory tract that comes out when coughing. Its color is described in reference books as a separate sign. Below is what white, yellow, green, rusty, and purulent sputum mean.

What sputum is and what types exist

Sputum is a pathological secretion of the tracheobronchial tree mixed with saliva and secretions of the nasal mucosa and paranasal sinuses. Normal bronchial secretion is mucus with macrophages and lymphocytes. Normally there is little of it, and it is swallowed. In illness, the volume of secretion increases — from small amounts to one and a half liters per day.

• Mucous — colorless and transparent, in catarrhal inflammation.
• Serous — liquid and foamy, without odor.
• Mucopurulent — viscous, yellowish or greenish.
• Purulent — with a putrid odor.

White and clear sputum

Clear colorless sputum is mucous. It occurs in catarrhal inflammation of the respiratory tract: at the beginning of an acute process or in chronic inflammation in the remission phase.

Yellow and green sputum: what it means

A yellowish and greenish color means an admixture of pus. Viscous mucopurulent sputum is described in bronchitis, pneumonia, bronchiectasis, and pulmonary tuberculosis. Purulent sputum — liquid, foul-smelling — occurs in suppurative processes: abscess, purulent bronchitis, gangrene of the lung. Bright yellow, canary-yellow sputum is associated with a large number of eosinophils in bronchial asthma and eosinophilic infiltrative process in the lung. Cough with yellow or green sputum is a reason to make an urgent appointment with a doctor.

Rusty sputum and sputum with blood

Rusty sputum may indicate lobar pneumonia. The color comes from hematin from red blood cells broken down inside the alveoli. There is no separate description of brown sputum in reference books. Sputum with streaks or clots of blood is hemoptysis. It is described in tuberculosis, pulmonary embolism, bronchiectasis, and Goodpasture syndrome. Black sputum with coal dust is found in pneumoconioses.

Purulent and foamy sputum

Usually sputum has no odor. A putrid odor occurs in gangrene or abscess of the lung; it is caused by the growth of putrefactive microorganisms. Foamy liquid sputum without odor is serous; it is described in alveolar pulmonary edema; a pink tinge is associated with diapedetic bleeding.

Sputum in pneumonia, sputum analysis, and when to see a doctor

Pneumonia is inflammation of the lungs, usually due to a bacterial or viral infection. In pneumonia, sputum may be mucopurulent and rusty. Symptoms: cough, shortness of breath, high temperature, chest pain, aching, fatigue, wheezing. In older adults, confusion is possible.

Sputum culture is a test that looks for the microbes that caused the infection. The sample is collected by deep coughing into a container. The thicker the sputum, the more likely it is to contain bacteria from the lower respiratory tract. Culture is observed for 2–3 days or longer. Normally there are no pathogens; sometimes bacteria from the oral cavity grow. A positive result helps in bronchitis, lung abscess, pneumonia, tuberculosis, exacerbation of COPD, and cystic fibrosis. The test has no risks.

See a doctor urgently: cough lasting up to 3 weeks, yellow or green sputum, chest pain, shortness of breath.

Sputum by itself is not a reason to call an ambulance. 103 or 112 — if breathing is difficult: the person is gasping, cannot speak; the skin, lips, or tongue are pale, blue, or mottled; cough with blood; sudden confusion, the person does not understand where they are; the child cannot be woken or is lethargic.

Terms. Sputum — secretion of the respiratory tract that comes out when coughing. Mucopurulent sputum — viscous, yellowish or greenish. Rusty sputum — with hematin from red blood cells. Sputum culture — a laboratory search for the causative agent.

Reference material: it describes signs but does not replace consultation with a doctor.

This content is for reference and does not replace a doctor's consultation. Medical disclaimer