Can someone help me understand this logic?

[Circularlogic]

I had some blood tests a few years ago due to sheer exhaustion. GP suggested iron levels were checked. I was told they were fine. Things didn’t improve and I’ve always had heavy periods, so was sent for some testing and have adenomyosis. My ferritin levels were checked again and I was told they were normal and having young children is tiring. After the third time I was able to see my tests and was told nothing to worry about as ferritin had improved (11-14). However, they prescribed iron tablets. I’ve been on the tablets for two years, my ferritin is still under 20, iron binding is 9. My hair is coming out in clumps, I’m cold nearly all the time unless it’s literally boiling, nauseous and just doggone exhausted. Why do they keep dismissing low iron as a cause - and if it’s nothing to do with iron, why do they keep telling me to take the iron tablets? I’m being sent to numerous appointments - latest is a camera down throat procedure. I’ve had to stop work. I’m sleeping for hours.

Thyroid.

being cold all the time and hair coming out is classic.

How were the rest of your bloods? Your struggle with iron is likely to be a symptom of something else if you're supplemented and still low, so as it's not the root cause they need to see what might be such as checking for a source of internal bleeding with the camera.

Your ferritin is low enough to cause fatigue, hair loss, and feeling cold. Doctors say “normal” but iron isn’t fixing it. Could be absorption or blood loss needs specialist check.