Do you know why you are low on iron?

I was diagnosed with iron deficiency microcytic anemia about two years ago with very very low iron. The reason was excessive monthly blood loss that lasted many years (I am a female, so I guess you know what I mean...). My symptoms were very apparent when doing sports: I could hardly run and cycling up a steep hill was a nightmare. My heart rate would go crazy and I could hardly breathe. At work I was frequently very sleepy, but I didn't see it as a symptom back then. And I was pretty pale, but I didn't see that either.

I had a course of iron injections and then a course of oral iron supplements. I still take iron supplements now once in a while because my iron levels are still not optimal.

I think I started feeling better about 2-3 weeks after the first injection. I cycle to work on daily basis so it was easy to monitor. It took me some months (3-4 maybe) until I could feel more or less fit again.