A health professional diagnoses mild, or subclinical,
hypothyroidism though a medical history and physical
examination. If your health professional suspects you have subclinical
hypothyroidism, you will have lab tests to confirm the diagnosis.
Subclinical hypothyroidism is diagnosed when you have:
Some people with subclinical hypothyroidism may test positive for
antithyroid
antibodies, which indicates they have
Hashimoto's thyroiditis, which may cause a gradual
loss of thyroid gland function.
Subclinical hypothyroidism should be watched closely. Up to 20% of
women over the age of 60 have subclinical hypothyroidism; about
2% to 5% of people with subclinical disease develop hypothyroidism every
year.1, 2
Some studies have shown that older adults with subclinical hypothyroidism may be more likely to have heart failure, but more research is needed.
Current research does not provide clear evidence to support treatment
of every person with subclinical hypothyroidism, and many doctors disagree
whether it should be treated. When making the decision to treat subclinical
hypothyroidism, you and your health professional will talk about the benefits of treatment (reduced symptoms) compared to the cost of medicine and monitoring symptoms. Some studies have shown that treatment of subclinical hypothyroidism may lower cholesterol levels, but more research is needed.