The TSH is the hormone from the pituitary (Thyroid Stimulating Hormone). The pituitary acts as a type of thermostat for thyroid behavior. If the pituitary senses too much hormone, it lowers its production of TSH. If it detects too little thyroid hormone, it increases its production trying to stimulate thyroid cells to produce more.
And, it acts as a type of running average. It does not read the current levels and instantly change its levels of TSH. In other words, there is a lag between attaining (or losing) normal levels of thyroid hormone, and the pituitary showing the change: the weight of the previous levels is still holding it back somewhat.
It is theoretically possible for our thyroid hormone levels to have reached normal at about the same time as the blood test. The TSH will not register as “normal” until the values have been constantly “normal” for a while.
But, if you continue to feel objective hyper symptoms and your thyroid levels are “normal” but your TSH is still suppressed, it might mean that whatever those normal thyroid values are, they are not quite “normal” for YOU. There’s a big range of normal for thyroxin (T4) for example. Some of us feel better at some parts of that normal but not at others.
Whatever, if you are experiencing troubling symptoms like chest tightness and weak muscles, you should make sure to inform your doctor.
