Taking a sample of your own blood is exhausting.

Let me explain: first, there’s an awful lot of preparation. There’s the alcohol wipe you have to use, the minutes (3-5) you have to spend with your hand under a warm tap to create blood flow, the massage you’ll need to give your palm if the skin fails to become adequately pink (indicating blood). You can expect your adrenals to come alive right before you press the needle down into your finger, causing your hand to shake.

And then there’s the blood itself. If you hit a good spot (left of centre on your index finger, I discovered, works well), it will flow faster than you can scoop it up into the vial. Your bathroom - I would recommend doing this over a sink - will look as though a crime has been committed. I had blood on my forehead at one point. I caught a glimpse of my reflection in the mirror and momentarily wondered if I’d gone mad.

Here’s something else to consider: I am perfectly healthy. There is no medical reason for me to be taking a sample of my own blood, posting it and waiting giddily for the results. But that, it turns out, is the whole point.

Why do I care so much about tracking my health?