John Muir once said: "tug on anything at all and you'll find it connected to everything else in the universe."
He was referring to the natural environment. His point was that you had to be really really careful about how you influence nature because things are connected in ways you can't even imagine. Even the simplest actions could have unintended consequences.
If John Muir had been a medical doctor, I'm pretty sure he would have said pretty much the same thing about the human body. Everything in the human body is connected to everything else, but nobody understands exactly how.
For example, I went to the doctor for the four billionth time today to have my blood pressure checked. It was high AGAIN which was beyond frustrating because I now (a) take two different medications to control it (b) have seen a nutritionist to help me get on a very low sodium diet (c) have been trying to stay physically active and loose some prednisone weight and (d) I have been taking my blood pressure at home for almost two weeks and it hasn't been that bad!!
To move me out of my frustration, my doctor asked me how I was doing otherwise. I said not that fantastic, actually, because I feel like I have an ear infection or sinus infection or something. There has been this crazy pressure in my ear - like I changed altitude and my ear won't pop - and it won't go away. It hurts. And now the lymph nodes on that side are hurting too. So, while we were checking to see whether or not I had an infection, I mentioned that I had taken some Sudafed but I wasn't sure whether it had helped.
Well at least the Sudafed helped with something - apparently it explained my high blood pressure. Apparently, a drug that is meant to relieve allergies and sinus pressure also raises your blood pressure. I'm not clear on exactly how my blood and my sinuses are related, though. At least these two things both have the word "pressure" in them (unlike the hacking cough). In any event, it is now perfectly clear to me that any attempt to fix one problem is my body is almost certain to have an effect on some other, seemingly unrelated part of my body.
Touche, John Muir. You were right about pretty much everything.