After 10 years of iron deficiency / anemia, I went to a hematologist while visiting my family abroad. He was able to diagnose the reason, and the treatment is basically the same (iron infusions) bit he suggests to always be done proactively rather than wait and see by blood tests. (He's suggesting 6 months intervals, whereas the GI - who's the one treating me under the NHS- is asking the GP to test me every 6-9 months-)
The problem is that obviously if say they test me on month 6 and the results are borderline, I have to wait 3 more months to get retested, and then it's up to 2 months for the iron infusion referral to kick in. Usually those last 3-2 months are a complete agony.
My condition is never going to improve and I'll need iron infusions for life, but the prospect of always having to wait to be within the NHS range, rather than doing it proactively is already making me feel quite low.