I've been on levothyroxine since diagnosis of hypothyroidism in 1990 at the age of 21. Gradually over the years I needed more supplement until it peaked at 175mcg approx. 2 yrs ago. Since then I've been diagnosed with rheumatoid arthritis which is treated with methotrexate and I've lost over 6stone in weight through diet and exercise. I noticed my hair was falling out towards the end of last year and put it down to my methotrexate. Following a routine blood test in January my thyroxine was lowered to 150mcg and I had to be re-tested in April. It was still to high and was lowered to 125 to be re-tested in July. My recent test shows it's still too high and I've been advised to drop to 100mcg. During this time my hair has continued to thin which really upsets me but I think it may be improving a little. I'm really confused as to why after over 20yrs on treatment my levels are suddenly too high and I'm having these problems. I wonder if the rheumatoid treatment is stopping my body attacking the thyroid but the GP doesn't seem to understand or care about reason. I just get called by the receptionist and told to drop my dose. Is it usual for it to take so long to find an optimum dose as I've clearly been overtreated since at least January and God knows how long before that. I've also been found to have a heart murmur during this time and it's all causing me to stress. Do you think I should be referred to an endocrinologist or are rising levels normal and within the scope of GP treatment? Any advice would be much appreciated as I'm thinking of making an appointment to see my GP next week to discuss.