No Treatment Required – This Represents Normal Thyroid Function
Your thyroid function tests are completely normal and require no intervention. A TSH of 0.384 µIU/mL falls well within the standard reference range (0.45–4.5 mIU/L), and when combined with normal T4, T3 uptake, and free thyroxine, this definitively excludes both overt and subclinical thyroid dysfunction 1.
Why These Results Are Normal
TSH of 0.384 µIU/mL is at the lower end of normal but not suppressed. Values below 0.1 mIU/L would indicate subclinical hyperthyroidism, but your level is nearly four times higher than that threshold 2, 3.
All thyroid hormone parameters are normal. The combination of normal TSH with normal free T4, total T4, and T3 uptake definitively excludes both overt and subclinical thyroid disease 1.
TSH has a sensitivity above 98% and specificity greater than 92% for detecting thyroid dysfunction; a normal result reliably excludes disease 1.
What This TSH Level Means Clinically
Low-normal TSH (0.1–0.45 mIU/L) with normal thyroid hormones does NOT indicate hyperthyroidism requiring treatment 2, 3.
Persons with TSH levels between 0.1 and 0.45 mIU/L are unlikely to progress to overt hyperthyroidism, and the rate of progression is significantly lower than in those with TSH <0.1 mIU/L 2, 3.
A TSH of 0.384 µIU/mL represents normal physiologic variation; TSH secretion is inherently variable due to pulsatile secretion, circadian rhythms, and other physiological factors 1.
When to Recheck (If Ever)
Asymptomatic individuals with normal thyroid function tests do not require routine screening intervals; recheck only if symptoms develop or risk factors emerge 1.
Symptoms warranting repeat testing include: unexplained weight loss, palpitations, heat intolerance, tremor, anxiety, or new-onset atrial fibrillation 4.
If you remain asymptomatic, no follow-up thyroid testing is needed 1.
Critical Pitfalls to Avoid
Do not treat based on a single borderline TSH value when all thyroid hormones are normal. TSH can be transiently affected by acute illness, medications, stress, or time of day 1.
Avoid over-interpreting normal physiologic TSH variation. Day-to-day TSH variability can reach 50% of the mean value, and serial measurements at the same time of day can vary by approximately 40% 1.
Never assume hyperthyroidism when TSH is in the 0.3–0.45 mIU/L range with normal free T4—this is within the normal reference range for most laboratories 1.
Special Considerations
If you have a history of thyroid disease, are taking levothyroxine, or have cardiac disease, the interpretation may differ—but for an otherwise healthy person with these results, observation without intervention is appropriate 2, 3.
Transient causes of low-normal TSH include recent acute illness, certain medications (dopamine, glucocorticoids), or recovery from thyroiditis; these should normalize spontaneously 1.