Hormones quietly steer your energy, mood, weight and sleep. Here we translate the hormone and metabolism tests — thyroid, cortisol, insulin, the sex hormones and more — into clear, doctor-written explanations.
Melatonin is the most misunderstood sleep aid on the shelf. Millions swallow it like a sleeping pill and expect to be knocked out — then feel let down when it does not work that way. Here is the shift that changes everything: melatonin is not a sedative. It is your body’s darkness signal — the…
Free T3 is the thyroid result that appears less often than TSH or T4 — but it measures the hormone that actually does the work. T3, or triiodothyronine, is the active thyroid hormone: the one that reaches your cells and sets the pace of your metabolism. What is surprising is where it comes from. Your…
Free T4 is one of the numbers that appears when a doctor checks your thyroid — and, alongside TSH, it is one of the most useful. T4, or thyroxine, is the main hormone your thyroid gland makes, and it acts like a throttle for the whole body, setting the speed at which everything runs. The…
Parathyroid hormone is your body’s main thermostat for calcium — the dial that quietly keeps the level in your blood steady from one hour to the next. It is made by four tiny glands in your neck, behind the thyroid, and although you rarely hear about it, it guards one of the most tightly controlled…
Aldosterone is a hormone you have probably never thought about, yet it quietly helps set your blood pressure every single day. Made by the adrenal glands that sit on top of your kidneys, it is your body’s master controller of salt and water balance — and, through that, of the pressure inside your arteries. When…
Growth hormone has a reputation it does not quite deserve — sold as an anti-ageing miracle by some, feared by others, yet genuinely vital to how your body grows and runs. Made by the pituitary gland, this single hormone does very different jobs depending on your age: in childhood it builds your height, and in…
Progesterone levels swing dramatically across the menstrual cycle — low in the first half, then surging after ovulation — which is why the timing of a progesterone test matters as much as the number itself. Progesterone is the hormone of your cycle’s second half and the key hormone of early pregnancy, working hand in hand…
DHEA levels quietly peak in your twenties and then fall, decade by decade, for the rest of your life — a decline that has made DHEA one of the most hyped “anti-ageing” supplements on the shelf. But what is this hormone actually for? Made by your adrenal glands, DHEA is a raw material your body…
Prolactin levels are easy to overlook, but this pituitary hormone can quietly explain a surprising range of symptoms — from irregular periods and a low sex drive to unexplained difficulty conceiving. Prolactin’s main job is to produce breast milk, so it’s naturally high during pregnancy and breastfeeding. Outside those times, though, a raised level can…
Thyroid hormones set the pace of your entire metabolism — how fast you burn energy, how warm you feel, and how your heart, gut, and mood tick along. The two that matter most are T4 and T3, and they’re usually read together with TSH, the pituitary signal that controls them. This guide explains what T4…