핵심 개념
Abnormal TSH levels require careful evaluation and management to determine the underlying cause and appropriate treatment approach.
초록
The article provides guidance from endocrinologists Angela Leung, MD, and Karen Tsai, MD, on how to approach and interpret abnormal thyroid-stimulating hormone (TSH) levels in primary care.
Key points:
- TSH is the preferred initial test to assess thyroid function, as it integrates information about thyroid hormone levels over time.
- A low TSH may indicate hyperthyroidism, often due to Graves' disease or temporary conditions like nonthyroidal illness or medication use.
- An elevated TSH suggests hypothyroidism, commonly caused by Hashimoto's thyroiditis or iodine deficiency.
- Confirming persistent abnormal TSH levels and evaluating for thyroid antibodies can help establish the underlying cause.
- Treatment decisions for hypothyroidism depend on the degree of TSH elevation and presence of symptoms.
- Clinicians should be cautious about over-treating subclinical thyroid dysfunction, as many cases resolve spontaneously.
- Endocrinology referral may be warranted for discordant test results, difficult-to-manage cases, or unexplained transitions between hyper- and hypothyroidism.
통계
If the TSH level remains persistently low, usually in the presence of high thyroid hormone (T3 and/or T4) levels, the most common reason for hyperthyroidism is Graves' disease.
If the TSH level is confirmed high and the thyroid hormone levels are low, the most common cause of hypothyroidism in the United States is Hashimoto's thyroiditis.
Globally, iodine deficiency is the most common reason for hypothyroidism.
If the TSH level is > 10 mIU/L, clinicians recommend levothyroxine hormone replacement.
A TSH level of 5-7 mIU/L may be an acceptable range for older patients, and they do not require levothyroxine.
A recent study on levothyroxine use found half of the prescriptions were unnecessary.
인용구
"If the TSH level is confirmed high and the thyroid hormone levels are low, the most common cause of hypothyroidism here in the United States is Hashimoto thyroiditis."
"If the TSH level is > 10 mIU/L, I recommend levothyroxine hormone replacement. A lot of published data support clinical benefit in this group."
"A recent study on levothyroxine use found half of the prescriptions were unnecessary."