The Dr. Z Answer Library
How can we help you?
Clear, sourced answers to the endocrinology questions patients actually ask, written and medically reviewed by a board-certified endocrinologist.
How can my labs be normal when I feel unwell?
Normal labs mean your results landed inside a statistical reference interval, not that nothing is wrong. Reference intervals are built to contain the middle 95 percent of a healthy reference group, so about 1 in 20 healthy people fall outside them, and people with early disease often fall inside. The other common reason is that the test explaining your symptoms was never ordered.
Written by an endocrinologist
Every answer is written and medically reviewed by Dr. Zahraa Sater, M.D., M.P.H., not a content team.
Reviewed on a schedule
Each answer shows when it was last reviewed and when its next review is due, so nothing goes stale unnoticed.
Sourced and plain-spoken
Written at an 8th grade reading level, with 2 to 6 checkable citations on every clinical answer.
Explore by topic
Four separate questions live under the word thyroid: function, autoimmunity, structure, and whether treatment is set correctly.
GLP-1 medicines are now approved for heart, sleep and liver outcomes, which changes who should take one and for how long.
Insulin resistance runs for years while glucose still reads normal, which is why the diagnosis usually arrives late.
PCOS is a metabolic and endocrine condition rather than a disease of ovarian cysts, and in May 2026 it was formally renamed.
Perimenopause is read from your cycle pattern, not from a hormone level, and the metabolic change starts before the final period.
A normal result is a statement about a population, not a verdict on you, and one flagged value on a big panel is often just arithmetic.
Behaviour change fails for measurable reasons: sleep, appetite and environment. Here is what the evidence supports, ranked honestly.
What root cause endocrinology means precisely, what it rules out, and which service fits what you are actually looking for.
Most asked
The questions patients bring up first, answered directly.
How can my labs be normal when I feel unwell?
Normal labs mean your results landed inside a statistical reference interval, not that nothing is wrong. Reference intervals are built to contain the middle 95 percent of a healthy reference group, so about 1 in 20 healthy people fall outside them, and people with early disease often fall inside. The other common reason is that the test explaining your symptoms was never ordered.
TreatmentHow do GLP-1 medications actually work?
GLP-1 medications copy a gut hormone your body already releases when you eat. Semaglutide and tirzepatide slow how fast the stomach empties, increase insulin release only when glucose is high, and change appetite signalling in the brain so hunger and food preoccupation fall. Tirzepatide acts on a second receptor, GIP, as well. Weight loss follows from eating less, not from burning more.
SymptomsHow do I know if I am in perimenopause?
Perimenopause is identified from your menstrual pattern and symptoms, not from a hormone level. The first dependable sign is a persistent change in cycle length of seven days or more. Hot flashes, broken sleep and mood changes usually follow. Most women start the transition in their forties, and menopause is only confirmed after twelve months with no period.
CausesHow does chronic stress affect metabolism?
Chronic stress raises cortisol and sympathetic nervous system activity, which push blood glucose up, favor fat storage around the abdomen, and disrupt sleep. The effect of ordinary life stress is real but modest. Large, clearly measurable metabolic damage from cortisol comes from Cushing's syndrome, a separate disease with its own physical signs and its own workup.
DiagnosisHow is PCOS actually diagnosed?
PCOS is diagnosed with the Rotterdam criteria: two of three features, which are irregular or absent ovulation, high androgens by symptoms or blood test, and polycystic ovarian morphology on ultrasound or a raised AMH. Look-alike conditions must be excluded first. In adults, if irregular cycles and high androgens are both present, no ultrasound is needed.
DiagnosisWhat does a TSH test actually measure?
A TSH test measures thyroid stimulating hormone, which is made by the pituitary gland, not by the thyroid. TSH is the pituitary's instruction to the thyroid. It rises when thyroid hormone is low and falls when thyroid hormone is high. TSH is therefore an indirect signal about thyroid output, not a measurement of thyroid hormone itself.
CausesWhat is insulin resistance, in plain terms?
Insulin resistance means muscle, liver and fat cells respond weakly to insulin, so the pancreas releases more insulin to keep blood glucose normal. Glucose can stay in range for years while insulin output runs high. Insulin resistance causes no reliable symptoms, and in practice it is inferred from glucose, HbA1c and related labs rather than measured directly.
Can't find your question?
Have it answered by Dr. Sater
Every answer here is written and reviewed by a board-certified endocrinologist. To have that judgment applied to your own history and labs, book a consultation.
Written and medically reviewed by Zahraa Sater, M.D., M.P.H. · Editorial and Medical Review Policy