You may remember that I don’t typically care much for numbers—how they can define us, how they can limit us, how I can’t escape them even when I wish I could. (Here’s the post all about that.)

I humbly submit an addendum to “Why I’m Not a Numbers Girl.” Don’t get me wrong, in most instances, I still feel that percents and ratios and variables and risk assessments too often fail to quantify what’s most important. I still don’t like that as patients, too often we’re reduced down to a list of stats and numbers (vitals, meds, dosages, surgeries, lab results).

But I recently (re) discovered that sometimes, numbers can actually better our understanding of ourselves. Not exactly earth-shattering news, I realize, and certainly all you diabetics who test blood sugar daily or patients who monitor blood pressure and other routine activities like that must be rolling your eyes at the obviousness of that statement, but it’s an important realization for me.

When I was acutely ill (in and out of the hospital for weeks at a time), the doctors trying to figure out what was wrong with me asked me to keep track of my peak flow meter readings. For those of you blessed with hearty lungs, a peak flow meter is basically a tube you breathe into that measures how much you can exhale. The lower the number, the more constricted your airways, so peak flows are a good way to predict respiratory trouble. I stuck with it for several weeks, filling in the little boxes in a notebook a doctor gave me…and then I went into the ICU again and everything got thrown upside down. When I came out of this hospital, I had a new team of doctors and a million other new things to consider and somewhere along the way, my little notebook disappeared.

And then last week, in the midst of spring cleaning my medications (so long, empty pill bottles! See you later, empty inhaler canisters!) I stumbled across my humble little peak flow meter. A desire for more order and predictability in my life coupled with an increasing interest in Microsoft Excel prompted me to re-instate the daily peak flow charting, this time with nifty little grids and columns.

The result? I’ve noticed a pattern: the days where my morning readings are especially low (they are never spectacular, even on my best days) correlate with the days where I wheeze more, cough more, and in general experience more fatigue. The days where my early morning readings are higher? I am able to go to the gym, I don’t spend half the day coughing, and I can get a lot more done.

Duh. I know you’re thinking it. I am, too. Somehow charting peak flows just slipped to the bottom of my priority list, far below all the other more time-consuming things I do to maintain my health. No, knowing my peak flow readings will not prevent my bad days altogether, but it will help me prepare for them and predict them. I understand my body and my symptoms so much better once I stopped long enough to pay attention to my internal warning signs.