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.
Acute stress results from the sudden onset of demands or events that seem to be beyond the control of the individual. This type of stress is often experienced as tension headaches, emotional upsets, gastrointestinal disturbances, and feelings of agitation and pressure.