An elevated ultrasensitive TSH usually indicates underactive thyroid (hypothyroidism)—either subclinical (normal free T4) or overt (low free T4). Repeat testing, measure free T4 and thyroid antibodies, review medications and symptoms, and consult your clinician. Treatment (levothyroxine) is considered for symptomatic patients, pregnant women, those with cardiovascular disease risk, or persistent TSH >10 mIU/L. Regular monitoring guides management.

Ultrasensitive TSH is a high-sensitivity blood test that measures very low thyroid-stimulating hormone levels (often down to about 0.01 mIU/L). It improves detection of subtle thyroid dysfunction, helps diagnose subclinical hyperthyroidism or persistent suppression during thyroid hormone therapy, and is used to monitor replacement or suppressive treatment. Results inform clinical decisions alongside symptoms and free thyroid hormone measurements.

To lower an elevated ultrasensitive TSH, see your clinician for dose adjustment or initiation of levothyroxine and regular monitoring. Take levothyroxine on an empty stomach, avoid calcium, iron or antacids within four hours, and maintain consistent timing. Evaluate for malabsorption, drug interactions, or iodine deficiency. Do not change medication without medical guidance; repeat TSH testing per your provider’s schedule.

A TSH test measures thyroid-stimulating hormone to evaluate thyroid function during pregnancy. Proper thyroid balance is essential for maternal health and fetal brain development. Early screening—especially in high-risk women or with symptoms—identifies hypothyroidism or hyperthyroidism. Abnormal TSH prompts further tests (free T4, antibodies) and treatment to maintain pregnancy-adjusted TSH targets and reduce risks to mother and baby.

High TSH usually signals hypothyroidism, which can cause modest weight gain because low thyroid hormone slows metabolism and can increase fluid retention. Weight changes are typically a few kilograms rather than dramatic. Treating hypothyroidism with appropriate thyroid hormone replacement often reduces or reverses much of this gain, though diet, activity, medications, and other conditions also influence weight.

If TSH is high, see your clinician for confirmatory labs (TSH and free T4) and to identify causes. Most cases are treated with levothyroxine replacement individualized by weight, age and comorbidities, with dose adjustments guided by TSH every 6–8 weeks. Address underlying causes (autoimmune thyroiditis, medications, iodine status), avoid interfering drugs, and arrange regular follow-up, especially in pregnancy or heart disease.