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.
The effects we are likely to see aren't just trauma from experiencing natural disasters, he added. We can also expect increases in long-term stress and anxiety from the aftermath of disasters, as well as increases in violence and crime rates as a result of higher temperatures or competition for scarce resources..