QUESTION: Is there such a thing as “low grade hyperthyroidism”? If so what are the tests? and treatments?
ANSWER: The Endocrine system is characterized by a gradation of dysfunction from none at all to extreme on both the overactive and the underactive ends of the scale. Medicine sometimes has trouble defining instances of dysfunction that are in the middle. And anything that is difficult to measure is difficult to determine how important that dysfunction may be.
The thyroid gland can have both low-grade hyperthyroidism and low-grade hypothyroidism. This can be called subclinical when the tests show dysfunction but there are no symptoms. There can also be the case in which people can develop symptoms that appear related to the thyroid but have no corroborating laboratory evidence that there is an illness.
Additional tests would include the free T4 and free T3, thyroglobulin, reverse T3 and antithyroid antibodies. You may have to investigate several key minerals including iodine as well as other hormone levels including progesterone and cortisol. In addition, the problems may originate in the gut with food sensitivities or in overactive autoimmunity. An ultrasound of the thyroid gland is frequently useful.
In general, thyroid dysfunction requires examination of the overall picture of multi-organ hormone balance, gut function, immune function, and nutrition.