Sputum or phlegm is pus like substance that is expelled from your throat. Sputum comes out when you have cough or allergic cold or respiratory tract infection. The color of the sputum is indicative of the disease and your doctor would often ask for it during diagnosis. The color of the sputum gains importance during laboratory test of sputum culture. Your doctor will complete the physical examination and collect complete medical history before making any decision. While giving the sputum sample in the lab, it is wise to take the first sputum in the morning which can give a clear picture. Sputum color may change depending on the foods and drinks you take during the course of the day.
- Sputum (Phlegm) Colors :
Sputum not only contains mucus but also cellular debris, micro-organisms and other immune cells. Some people may find traces of blood in the sputum. It may contain dust and other toxic substances in the body. Sputum is of various colors like white, grey, clear, green, yellow, red, brown, pink, black and rust colored. Let us discuss about every color of the sputum and its significance.
Clear or White Sputum :
It is quite normal to get clear sputum once in a while, but if you are getting white sputum in excess it can be indicative of some internal disorders. Some of the conditions like chronic bronchitis, asthma and pulmonary edema can produce clear or white sputum. The sputum color can be clear to whitish if you have moderate respiratory tract infection. People with chronic asthma can get thick whitish (cottage cheese like) sputum. The color of the sputum would be clear white or grey for those with chronic bronchitis. Medical condition like pulmonary edema can cause clear white but frothy sputum. Other conditions like allergic cold, postnasal drip and GERD can produce white or clear sputum.
Yellowish Sputum :
White to yellow colored sputum is often indicative of infection and allergic condition. Excess of eosinphils and neutrophills can block the airways causing yellowish sputum. Conditions like acute bronchitis and pneumonia can produce yellow sputum. If the sputum is thick and yellowish it can be due to infection caused by virus or bacteria. However this is not the case all the time and it is not necessary that you carry some infection in your body if you get yellow sputum. According to a recent publication of European respiratory journal, only 46 persons out of 100 people with yellow sputum were detected to have some sort of infection.
Green Colored Sputum :
Getting green sputum can be due to chronic infection. A protein compound called neutrophils releases some green colored enzymes (verdoperioxidase / myeloperioxidase) during the process of breakdown. This can cause green sputum. It is the immune system that sends loads of WBC containing neutrophils to the site of infection which breaks down producing green color. Affected person can get large volumes of sputum if he/she is suffering from chronic infection. Chronic conditions like pneumonia (lung infection), chronic bronchitis, and abscess present in the lungs, and cystic fibrosis can cause greenish sputum. However you cannot conclude that you are infected with any of these diseases if you have green sputum. There are many other symptoms like fever, cough, malaise and loss of appetite and much more diagnostic procedures to detect infectious condition.
Brown or Black Colored Sputum :
Brown sputum can be due to presence of blood. Red blood cells are broken down to release enzymes called hemosiderin. People who are regular smokers can have brown or black sputum due to excess of tar or resin and other pollutants present in the cigarette. The body’s mechanism fights to expel these irritants from the lungs as quickly as possible in the form of black sputum. For some people eating certain foods like lots of chocolates and coffee can cause brownish sputum. Certain medical conditions like chronic pneumonia and bronchitis can cause greenish or brown to black sputum. Infectious diseases like TB and lung cancer can cause brown sputum. People working in pollutant atmosphere like that of mines and coal fields are highly prone to get brown to black sputum.
Red or Pink Colored Sputum (Phlegm) :
Red colored sputum is indicative of presence of blood in it. Pulmonary edema (building up of excess of fluid in the lungs) can cause pink or red sputum. Red sputum can be due to leakage of blood somewhere in the respiratory tract. People living with heart problems can also get red sputum. Blood streaks can be seen with mucus and for some people the entire mucus color may change to reddish pink. Blood clot inside the body can also cause rust colored mucus. Red frothy sputum can occur due to lung cancer which advances to brown colored sputum if the cancer has widespread in the body. Medical conditions like pulmonary embolism can cause bright red colored sputum. Lung abscess, chronic heart failure, lung injury and bleeding disorders can cause brownish red or pink sputum.