Phlegm originates from the lungs. It is different from the mucus that is produced in the nasal passages. A common cause of phlegm is post nasal drip which is a symptom of sinus infections, colds, flu and inhalation of irritants. The diagnosis of the underlying condition could be made from the color of the phlegm.
A flow chart is a type of diagram representing a process using different symbols containing information about steps or a sequence of events. Each of these symbols is linked with arrows to illustrate the flow direction of the process.
There are many different types of flowcharts, and each type has its own repertoire of boxes and notational conventions. The two most common types of boxes in a flowchart are: 1  a processing step, usually called activity, and denoted as a rectangular box. 2  a decision, usually denoted as a diamond.