Typically it is said when listening to someone talking-- it is a polite way to let them know that you are paying attention. Think of it as going 'mm' or 'ah'.
In addition stress can have direct effects on the skin (rashes, hives, atopic dermatitis, the gastrointestinal system (GERD, peptic ulcer, irritable bowel syndrome, ulcerative colitis) and can contribute to insomnia and degenerative neurological disorders like Parkinsonâs disease.
Pressure points. Even short-lived, minor stress can have an impact. You might get a stomach-ache before you have to give a presentation, for example. More major acute stress, whether caused by a fight with your spouse or an event like an earthquake or terrorist attack, can have an even bigger impact.