Around in sickness or in health,
I come in complete and utter stealth.

Sports can create me,
While advil subside me.

I can come out with too much booze,
Or even without enough snooze.

Some say I happen when you get a bang,
At my worst, I can be described by this musical twang.

With me, age has no bounds
Cause when I hit you, your head pounds.

What am I?