I recently had a blood test to check up on my iron levels (and a few other things).
My iron and ferritin (iron store) levels are still very low and I need to continue supplementation, which I am doing. It also means I need to start eating things like liver a few times a week. I really don't like beef liver, so I'll try chicken liver, which is more mild in taste and while it has less iron/vitamin B12, it still has them in ample amounts and enough to help me replenish my iron/ferritin.
In addition to this, my TSH (thyroid stimulating hormone) was quite high. It was in the normal range, but right at the top of the normal range and basically double what it was only three months ago! This is probably because my thyroid is getting hypothyroid due to the multiple nodule goitre I have on my thyroid. Apparently high stress (which I am under at present) can increase the amount of cortisol circulating in the body and this can cause the thyroid to function less effectively as well.
With the low iron/ferritin levels and high TSH (potentially hypothyroidism) results, it means I will get more tired, feel lethargic, feel cold easily and put on weight easily. The higher TSH results also mean more bleeding during menstruation. Thyroid disorders often go hand-in-hand with PMS and PMDD!
Low iron/ferritin levels not only have the above symptoms, but they can make you feel depressed and anxious, as part of the symptoms. Once the iron/ferritin levels go back to normal, these symptoms also disappear! This means that PMS symptoms can become worse if iron levels are too low and become more like PMDD symptoms.
The blood test was taken when I was still really sick from the flu and I had my periods at the time, so that is probably why they the iron and ferritin levels were extra low.
I have just ovulated. I know because of the symptoms I get during ovulation is the same every month. This means PMS is coming!