An early underactive thyroid with raised TSH but still-normal thyroid hormone levels and few symptoms. Blood testing detects the elevated TSH before overt hypothyroidism develops.
Our comprehensive check-up screens for subclinical hypothyroidism and hundreds of other conditions.
The ratio of free thyroxine (fT4) to thyroid-stimulating hormone (TSH) provides additional insight into thyroid function by evaluating how the pituitary gland responds to circulating thyroid hormone levels. It can reveal subtle thyroid dysfunction that individual fT4 or TSH values alone may not capture.
fT3 / fT4 ratioThe ratio of free triiodothyronine (fT3) to free thyroxine (fT4) reflects how efficiently your body converts the storage thyroid hormone (T4) into the active form (T3). A low ratio may indicate impaired conversion, which can occur with stress, illness, selenium deficiency, or certain medications — even when individual thyroid values appear normal.
Free T4 (fT4)Free T4 is produced by the thyroid gland and converted to active T3 in body tissues.
Free T3 (fT3)Free T3 is the active thyroid hormone that regulates metabolic activity and energy use in cells.
TSHControls thyroid hormone production, which regulates metabolism and energy. Thyroid dysfunction affects many body systems and can cause fatigue, weight changes, temperature sensitivity, and mood disturbances.
