OP (PINK DOLLY): You have all of the signs of hypothyroidism (underactive thyroid), hair loss, muscle pains, tiredness, and headaches, in fact they are classic symptoms. Is your skin very dry? Do you sometimes feel as if you have a "brain fog?", do you feel depressed or anxious?
There is currently a lot of controversy about the way the doctors in this country diagnose hypothyroidism. The thing they measure (TSH) can be an unreliable way of telling if someone is hypothyroid, and also in the UK the "normal" range that they use is nearly twice that in the US and Germany. So many people are suffering in the UK but not being diagnosed by their GPs, bhut would have been treated in other countries.
Hypothyroidism affects all of the systems in your body, and so it can affect lots of things and you can have strange symptoms and signs of it. The other thing to note is that a common cause of high platelets is auto immune disease - and most people in the UK who have hypoT at a young age have the autoimmune version. These are also the people who tend to be diagnosed as normal by blood tests while experiencing symptoms.
If you suspect this is the case, then ask your GP to test for the antibodies.
One of the easiest ways to test yourself is to take your temperature first thing in the morning before getting up. Normal temp is 37c, if it is 36.8c or lower, then you possibly have hypothyroidism, if it it 36c or lower, then this is almost certain! This is most accurate during your period. The reason for this is hypothyroidism slows down your metabolism. You may also have undeserved(!) weight gain and slow resting heart rate.
I know all of this as I am a hypothyroid sufferer, and have had to learn lots about it, as my GP left me ill.
If you would like to know more, then feel free to PM me, or you could have a look at one fo the thyroid patient sites - google Thyroid patient advocacy.
Take Care
Leah x