I am having palpitations, sweating, feeling generally unwell and low. There is a history of thyroid problems in my family and I have been tested about four times over the last 5 years. I have great difficulty in losing weight, I eat a very low fat diet as I have gallstones, but cannot seem to lose any weight. Is it possible that the tests I have had for thyroid disfunction could be borderline thereby not detected. I seem to have yearly bouts of the same symptoms and each time go back to my doctor for advice, but don t seem to get anywhere.