lab-guides
How to read your biomarkers: HbA1c, TSH, lipid panel, vitamin D, ApoB and more — what each marker means, optimal ranges by age, every claim sourced.
Bilirubin — The Red-Cell Waste Product Your Liver Clears
Bilirubin is the waste product left when red blood cells break down. The direct/indirect split — not the total alone — is what determines the follow-up.
Serum Calcium — Bone, Parathyroid and Kidney in One Value
A calcium blood test measures the calcium circulating in your blood — not the calcium in your bones, which is why an out-of-range result is followed up rather than corrected with a supplement.
ALP — Liver and Bone in One Number
Alkaline phosphatase is concentrated in the liver, the bile ducts and the bones — which is exactly what makes a raised value ambiguous until you know which of the three it came from.
PSA — What the Test Does and Does Not Settle
PSA screens for prostate cancer but cannot show what is causing an abnormal level. Screening and the treatment it can lead to may cause more harm than benefit for many men — a shared decision, not a box to tick.
Albumin — The Protein That Carries Everything Else
Albumin is the main protein in your blood: it keeps fluid inside the vessels and helps carry hormones, vitamins and enzymes — and it changes how total calcium on the same panel is read.
Electrolytes — Sodium, Potassium, Chloride, Bicarbonate
The electrolyte panel measures sodium, potassium, chloride and bicarbonate — minerals that help control fluid balance and acid-base (pH) balance.
Iron Studies — Serum Iron, TIBC and Transferrin Saturation
Iron studies are a group, not a single test: serum iron, TIBC and transferrin saturation, read with ferritin, show whether the iron in your blood is too low or too high.
CMP — The 14 Numbers on Your Annual Panel
The comprehensive metabolic panel is fourteen measurements from one blood draw: glucose, electrolytes, kidney markers, liver enzymes and proteins.
CBC — What the Full Blood Count Shows
The complete blood count measures red cells, white cells and platelets — a common test that is often part of a routine checkup.
Urine ACR — Albumin-to-Creatinine Kidney Marker
The urine albumin-to-creatinine ratio measures albumin passing into the urine. Above 30 mg/g is higher than normal and may be a sign of kidney disease.
Progesterone — Luteal-Phase Confirmation
Progesterone is made mainly after ovulation. Read a mid-cycle draw against the lab's range (MedlinePlus: 5–20 ng/mL). The cycle day of the draw decides which range applies.
Selenium — Thyroid + Antioxidant Cofactor
Selenoproteins help convert thyroid T4 to active T3 and protect the thyroid. Deficiency is rare in the US, and Brazil nuts are high enough to exceed the upper limit.