The most common causes of brown phlegm are smoking and exposure to second-hand smoke; a number of other environmental issues like air pollution and dust may also be to blame. Sometimes a person’s diet could trigger the production of phlegm as well. In more serious cases the root cause could be a respiratory infection or lung problem, though in these instances the phlegm tends to be on-going, which means that it doesn’t go away on its own — and in fact may actually get worse as time goes by. People are often alarmed when they first start coughing up brown phlegm, but it’s rarely anything to worry about. Just the same, anyone who is worried about their condition, particularly if the phlegm is accompanied by other symptoms like wheezing or fever, should usually get the advice of a qualified medical provider.
Phlegm is a thick, tacky substance that is sometimes expelled out of the body through coughing. It can come in a number of colors, such as white, yellow, green, and brown. It’s really similar to mucus, and in fact many experts say that the two substances are biologically identical. The difference in title is often related to where in the body each occurs, rather than primary function. On this understanding, phlegm is mucus that occurs in the respiratory tract, and is usually triggered by some sort of irritant.
Some mucus or phlegm is almost always in the throat and lungs, and is one of the main ways the body moves foreign particles like dust through the lungs. Small particles are often inhaled by accident, and moving them out is a relatively easy way for the body to maintain its efficiency. The lung’s cilia, which are cells that line the lung walls, are where the mucus is produced. These contain hair-like protrusions that essentially act to “sweep” the particles away.
People don’t usually notice their phlegm or know what color it is until there’s so much of it that the body needs to expel some. When something triggers an increased production, people often find themselves coughing up or spitting up phlegm. A brown color is usually considered unusual, though there are many possible explanations.
Concerns for Smokers
Smoking is one of the most common causes of brown-colored phlegm. When people regularly intake the smoke from cigarettes, cigars, or pipes, in most cases they’re breathing in more than just nicotine smoke — they’re also getting a range of resins, tars, and other chemicals. These tend to become trapped in the lungs. Heavy smokers will often cough up a small quantity of brown mucus, especially in the morning, and in most cases this is just a normal part of the lungs trying to clean themselves and expel the foreign particulates.
Individuals who are trying to quit smoking may also find themselves coughing up large quantities of brown phlegm. After a person quits, the cilia in the lungs, which have often been damaged or at least slowed by smoking, begin to work at a fuller potential again. These tiny hair-like projections then begin to sweep out the large quantities of phlegm caught in the lungs. This process can last for months in some individuals.
People who live in areas with very polluted air might also cough up brownish phlegm from time to time. Dust and dirt can also be a cause. When cleaning a dusty room or working around blowing sand or dirt, tiny particles can get caught in the throat. This mucus will then be coughed up, and the resulting phlegm will appear brown and grainy. In nearly all cases this is a temporary condition, and will go away as soon as the exposure has stopped.
Food and Drinks
Certain foods and drinks can cause a person's phlegm to appear brown. This is usually harmless, although it can be worrisome. Chocolate, red wine, and dark sodas can all temporarily alter the color of a person’s phlegm.
Infections and Health Problems
Certain respiratory or lung infections are more serious causes. Usually when a person gets a respiratory illness, the lungs will begin to produce more mucus than normal to trap certain bacteria and other foreign matter. Brown phlegm is a common sign of chronic bronchitis, for instance, and more serious respiratory infections, such as lung cancer or emphysema, might also be present.
A lot of things can possibly contribute, but getting to the root of the exact cause almost always requires an exam by a qualified medical expert. Anyone who is worried about the phlegm they’re coughing up, particularly if the problem has been going on for some time, is usually advised to get a medical check-up just to rule out more serious conditions.