Explained,
by topic

Where the numbers that dismiss you actually came from: who set each threshold, in what year, from which population — and what the research says now. One column, with its documents on the table.

• The Receipts Where Your Lab's Ferritin Floor Actually Came From The lower limit printed beside your ferritin result is a statistical interval, not a threshold for having enough iron. In a survey of 23 North American laboratories, 18 reported female 7 min · October 6, 2026

Ferritin, transferrin saturation, iron deficiency without anaemia, supplements, infusions, and the gap between a normal result and enough iron.

• Iron and ferritin Ferritin Normal but Iron Low? Check Saturation and CRP Neither number decides alone. Ferritin, the iron your body keeps in storage, can climb with inflammation while the iron travelling in your blood falls. Ferritin under 100, transferrin s 7 min · October 6, 2026
• Iron and ferritin Iron Deficiency Without Anaemia: Why Tired Is Not In Your Head Yes, low iron can flatten you while your blood count stays normal. Anaemia is the last stage of iron deficiency, not the first. In a double-blind trial of 164 women aged 18 to 45 whose 6 min · October 6, 2026

TSH, free T3 and T4, antibodies, subclinical hypothyroidism, and why a result inside the range can still come with symptoms.

• Thyroid and Hashimoto's Mildly Raised TSH: Does It Go Away on Its Own? Often, yes. In one review, 62% of raised TSH results came back normal on retest . TSH is the signal your brain sends to the thyroid, and one high reading catches a single moment in time 7 min · October 6, 2026
• Thyroid and Hashimoto's Hashimoto's With a Normal TSH: Can It Still Cause Symptoms? Possibly, yes. In 108 euthyroid Hashimoto's patients, symptoms were more common than in 57 healthy controls and tracked antibody levels, not thyroid hormones . That is correlation. No r 9 min · October 6, 2026

The decade before menopause: cycle changes, sleep, mood, weight, hot flushes, and what is testable and what is not.

• Perimenopause Waking at 3am in Perimenopause: What Trials Say Helps Behavioural methods worked best in trials: CBT-I, a structured talking course built for sleep, plus acupuncture, yoga and massage . None added hours of sleep. They changed how sleep fee 7 min · October 6, 2026
• Perimenopause Anxiety in Perimenopause: What Is Shown and What Is Guessed Anxiety and hot flushes rise together as the transition goes on. Two long studies, one following women for six years and one for ten, found it . Why they travel together is not settled: 7 min · October 6, 2026
• Perimenopause Perimenopause Symptoms in Your Early Thirties: Check Your Cycle Symptoms alone do not make perimenopause, and in your early thirties they rarely settle the question. Clinicians look at what your periods do over months: gaps getting longer, some mont 8 min · October 6, 2026

What each hormone does, how it is measured, when in the cycle to measure it, and what the numbers do and do not mean.

• Oestrogen, progesterone, testosterone Which Day of Your Cycle to Test Estradiol and Progesterone Book progesterone seven days before your next period is due, counting back from it. Book baseline estradiol, the main oestrogen, on days 2 to 5, counted from the first day of real bleed 7 min · October 7, 2026

Cortisol testing, the adrenal-fatigue claim, sleep, blood sugar, and what the evidence actually supports.

• Cortisol and the stress axis Cortisol Symptoms and Adrenal Fatigue: What Testing Can Prove Adrenal fatigue is not a recognised diagnosis. No endocrinology society has accepted it, and a review of 58 studies on cortisol and tiredness found conflicting results almost every time 6 min · October 6, 2026

SIBO, bloating, the oestrogen-gut connection, food reactions that appear in your forties, and what is testable.

• Gut and hormones Is Your Bloating Hormonal or Gut? A Diary Can Show You Bloating that follows the calendar leans hormonal. Bloating that follows meals leans gut. Both can happen at once. A diary of four things, kept for two months, shows which pattern is yo 7 min · October 7, 2026

Hair shedding, exhaustion, brain fog, weight changes, anxiety, cold hands, broken sleep: what each one points at, and which test settles it.

• Symptoms with no name yet Hair Shedding After an Illness Is Real, and It Can Reverse Yes, shedding after an illness or a stress is a known condition, telogen effluvium, which means shedding when many hairs drop out at once, and it is reversible . The fork: if you are th 7 min · October 6, 2026
• Symptoms with no name yet Which Blood Tests to Ask For When Your Hair Is Shedding Ask for three blood tests: ferritin, thyroid (TSH with free T4) and vitamin D. If the scalp itself looks different, with patches, itching, redness or pain, the route changes: you need a 8 min · October 6, 2026

Reference ranges and where they come from, what to ask for, when to test, and how to read a printout without a medical degree.

• Reading your own labs Your Blood Test Range Is Built From Other People's Results An H or an L next to your result means it sits outside the middle of the people one lab measured. It is a reason to ask a question. A plain "normal" means you sit inside that middle, an 7 min · October 7, 2026
• Reading your own labs How to Explain Your Symptoms in a Short Doctor Appointment One page, one opening sentence and one ask can change what a ten-minute appointment does. The fork is simple. Holding a borderline result? Ask about that result. Everything came back no 9 min · October 7, 2026
• Reading your own labs Blood Tests to Ask For When You Are Tired All the Time Ask for a short first-round list. Nine items: full blood count, ferritin with transferrin saturation, TSH with free T4, thyroid antibodies, B12, HbA1c, CRP, liver and kidney tests, coel 10 min · October 6, 2026
• Reading your own labs Can a Blood Test Show Perimenopause? It Depends on Your Age Usually no. Over 45, the UK's NICE menopause guideline tells doctors to diagnose perimenopause from your symptoms and cycle, without a blood test. Between 40 and 45 it allows an FSH tes 7 min · October 6, 2026