The thyroid gland — a small, butterfly-shaped gland at the base of your neck — produces hormones that regulate virtually every metabolic process in your body. Too much, and everything speeds up. Too little, and everything slows down. Yet thyroid disorders are frequently missed because their symptoms overlap with dozens of other conditions.
The Thyroid Hormones
TSH (Thyroid Stimulating Hormone) — produced by the pituitary gland, TSH tells the thyroid to produce more hormone. Counterintuitively, a high TSH means the thyroid is underactive (the pituitary is shouting louder trying to get a response). A low TSH means the thyroid is overactive.
T4 (Thyroxine) — the main hormone produced by the thyroid. Relatively inactive; converted to T3 in tissues.
T3 (Triiodothyronine) — the active form. Controls metabolic rate, body temperature, heart rate, and much more.
Free T3 and Free T4 — the unbound fractions actually available to cells. More informative than total levels.
Signs of Hypothyroidism (Underactive)
- Weight gain despite unchanged diet
- Fatigue and sluggishness
- Cold intolerance
- Constipation, dry skin, hair loss
- Depression, brain fog
- Elevated cholesterol
Signs of Hyperthyroidism (Overactive)
- Unexplained weight loss
- Heart palpitations, rapid pulse
- Heat intolerance, excessive sweating
- Anxiety, tremor
- Diarrhoea
