Sleep efficiency is one of the most useful numbers your smartwatch or ring quietly reports each morning — and one of the least understood. It is simply the share of your time in bed that you actually spend asleep, written as a percentage. You can be in bed for eight hours and still have poor…
Iodine is one of the smallest entries on any nutrition label and one of the most important — because without it, your thyroid simply cannot make its hormones. This trace mineral has a single, non-negotiable job: it is the raw material your body builds thyroid hormones from, and those hormones set the pace of your…
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…
Pulse pressure is a number hidden in plain sight in every blood pressure reading — the gap between the top and bottom figures. A reading of 120/80 has a pulse pressure of 40. It’s rarely mentioned at a check-up, yet it can reveal something the two numbers alone don’t: how stiff or flexible your arteries…
Iron studies can look baffling: a cluster of results — serum iron, transferrin, TIBC, saturation, ferritin — that seem to pull in different directions. But they’re designed to be read together, and as a group they tell a clear story about whether your body has too little iron, too much, or just enough. This guide…
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…
Vitamin C is the supplement people reach for at the first sign of a sniffle — but does it actually work, and what else does it do? Vitamin C is a water-soluble vitamin your body can’t make or store, so you need a regular supply from food. It builds collagen, acts as an antioxidant, supports…
Albumin levels rarely make headlines, but this single protein quietly keeps your blood where it belongs and ferries vital cargo around your body. Albumin is the most abundant protein in your blood, made entirely by your liver. When its level drops, fluid can leak out of your blood vessels and pool in your tissues —…
If your watch nags you to hit 10,000 steps a day, here’s some freeing news: that number was never based on science. It came from a 1960s marketing campaign, not a study. So how many steps a day do you really need? Research now points to a more achievable answer — and to the reassuring…
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…