In order to understand whether throwing up phlegm or swallowing it is better, it is important to understand exactly what phlegm is and the role it plays in the overall health of the human body. Essentially, phlegm is a substance that is created by the mucous membranes of the respiratory tract in the human body and is primarily concerned with trapping any foreign bodies and substances that may be causing certain illnesses. The foreign bodies mentioned include the various bacterium and viral organisms that are known to cause a number of respiratory illnesses such as pneumonia, bronchitis and even a simple cough. Analyzing the phlegm is also a very popular method of diagnosis of certain respiratory conditions as a patient suffering from a common cold is seen to have yellowish brown phlegm while one that is suffering from an infection could be seen to have greenish brown phlegm. Under normal circumstances when the body is not suffering from any kind of respiratory illness, the phlegm will appear to be clear.
Some of the more prominent symptoms when the body starts to produce excessive phlegm include shortness of breath and difficulty in breathing, a constant cough, soreness of the throat as well as a constant need and urge to clear ones throat.
Although there are a number of cultures and communities that believe that the only way to get rid of the mucus in throat is by throwing up phlegm, swallowing it does not pose any medical threat. When one chooses to swallow the phlegm, the acids present within the stomach measure at a rate of about pH 4 - making it strong enough to almost instantly kill any infection that might be present. The only drawback of this method of getting rid of mucous is the personal aversion that some people tend to experience. Moreover, a lot of how you get rid of the mucous depends on your physical surroundings. For example, spitting it out while alone on a road or open land may be seen as acceptable by some, but spitting it out when in the midst of high class company in an environment of rich taste will most likely be seen as a socially unacceptable action. If you experience severe phlegm buildup in the chest cavity, spitting it out to have a closer look at the color will help identify how serious the internal causing condition is while the presence of blood may prompt you to see a doctor as soon as possible.
answered by G M