Blood tests - too many / but not enough

[Fearless36]

I'm finding as the years progress that when it comes to illness/sickness, when I need to do more tests its getting more difficult to get blood out of my fingers onto the strips. I am talking about those times when you have colds/flu - and you do them before and after eating. Is it just me. First week is fine, but thereafter its like my fingers dry up somehow?

Any tips/suggestions