91 biomarkers

Oxygen-carrying protein in red blood cells; the central screen for anemia and erythrocytosis.

Average red cell volume; the first axis of anemia classification.

Coefficient of variation of red cell size; an early and prognostic marker.

Anucleate fragments central to hemostasis; a sentinel for inflammation, marrow function, and consumptive disease.

Total leukocyte count; meaningful only with the differential.

Young red cells; the bone marrow's response to anemia.

Acute-phase protein that binds free hemoglobin; falls in intravascular hemolysis.

Iron-storage protein; the single best marker of body iron stores — but also an acute-phase reactant.

Iron in transit; complements ferritin to discriminate deficiency, overload, and inflammation.

Iron-transport protein; rises in deficiency, falls in inflammation and malnutrition.

Principal extracellular cation; a marker of water balance, not salt intake.

Principal intracellular cation; small shifts have large electrophysiologic effects.

Major extracellular anion; key to acid-base diagnosis via the anion gap.

Principal extracellular buffer; the metabolic axis of acid-base.

Cytosolic enzyme released from any injured cell; nonspecific marker of cell turnover or hemolysis.

Skeletal/cardiac/brain enzyme; the workhorse marker of muscle injury.

End-product of purine catabolism; elevated in gout, tumor lysis, and metabolic syndrome.

Muscle-derived metabolite cleared by glomerular filtration; the practical GFR surrogate.

Serum-creatinine–based estimate of glomerular filtration rate; the operating definition of CKD stage.

Low-molecular-weight protein freely filtered; GFR estimator independent of muscle mass.

Urea reflects protein metabolism, GI bleeding, and renal perfusion — only partly GFR.

Glomerular permeability marker; the earliest indicator of diabetic and hypertensive nephropathy.

Liver-specific aminotransferase; the most useful single marker of hepatocyte injury.

Aminotransferase shared between liver, muscle, heart, and red cells.

Sensitive but non-specific marker of hepatobiliary injury and enzyme induction.

Cholestatic and bone marker; isoenzyme separation clarifies origin.

Heme-degradation product; pattern reveals pre-, intra-, or post-hepatic disease.

Major plasma protein; reflects synthesis (liver), losses (kidney/gut), and inflammation.

Non-invasive fibrosis estimate from age, AST, ALT, and platelets.

The principal cardiovascular risk lipoprotein; treatment target in primary and secondary prevention.

Cholesterol carried in HDL particles; an inverse risk marker but not a treatment target.

Reflects VLDL/chylomicron remnants; a metabolic-syndrome and pancreatitis marker.

Total atherogenic-particle count; the most accurate single-value cardiovascular risk marker.

Genetically determined LDL-like particle with prothrombotic kringle domain; an independent cardiovascular risk factor.

Plasma glucose after ≥8 h fast; the simplest dysglycemia screen.

Integrated glycemia over the prior 8–12 weeks; the diagnostic and monitoring workhorse.

Anabolic hormone; the earliest detectable signal of insulin resistance.

Calculated index of insulin resistance from fasting glucose × fasting insulin.

Pituitary feedback signal; the most sensitive screen for primary thyroid dysfunction.

Active fraction of T4; the prohormone of T3.

Active hormone at the receptor level; useful in suspected T3-toxicosis and conversion problems.

Marker of autoimmune thyroiditis (Hashimoto's, Graves').

Glucocorticoid output of the HPA axis; diurnal sampling matters more than absolute value.

Adrenal androgen precursor; declines with age and reflects chronic adrenal output.

Anterior pituitary lactotroph hormone; tonically inhibited by dopamine.

Hepatic mediator of GH action; integrated marker of GH activity over days.

Anterior pituitary corticotroph hormone driving adrenal cortisol synthesis.

Total androgen; influenced by SHBG. Always interpret with SHBG and free/bioavailable testosterone.

Carrier protein modulating bioavailability of testosterone and estradiol.

Primary estrogen in cycling women; informs ovarian reserve, menopausal status, IVF response.

Pituitary gonadotropin; surge triggers ovulation, drives Leydig-cell testosterone.

Drives ovarian follicle development and Sertoli-cell spermatogenesis support.

Granulosa-cell product; the best estimate of ovarian reserve at any cycle phase.

Bioavailable testosterone; preferred when SHBG is altered.

Luteal-phase steroid; ovulation confirmation and pregnancy support.

Acute-phase reactant; high-sensitivity assay refines cardiovascular risk in low values.

Indirect inflammation marker; useful in temporal arteritis, polymyalgia rheumatica, and osteomyelitis.

Coagulation protein and acute-phase reactant; persistently high values increase CV risk.

Methionine metabolite; high values reflect B-vitamin deficiency and modest CV risk.

Cardiac wall-stress marker; rules out heart failure with high NPV.

Myocyte-specific contractile protein; defines myocardial injury at the 99th percentile.

Cofactor for DNA synthesis and homocysteine remethylation; deficiency causes macrocytic anemia and neuropathy.

1-carbon donor; deficiency causes macrocytic anemia, neural tube defects, and homocysteinemia.

Storage form of vitamin D; the standard measurement of vitamin D status.

Specific marker of intracellular B12 deficiency; rises before serum B12 falls.

Cofactor for >300 enzymes; serum reflects only ~1% of body stores.

Essential anion in ATP, DNA, and bone; regulated by PTH and FGF23.

Cofactor for >300 enzymes; serum is a poor measure of body stores.

Tightly regulated by PTH and vitamin D; correct total Ca for albumin or measure ionized.

Calcium-regulating hormone; central to differentiating causes of hyper/hypocalcemia.

Extrinsic and common pathway; standardised across labs as INR for warfarin monitoring.

Intrinsic and common pathway; monitors UFH and screens for factor deficiencies.

Fibrin degradation fragment; sensitive but non-specific marker of active fibrinolysis.

Pancreatic enzyme; preferred marker for acute pancreatitis (more specific than amylase).

Pancreatic + salivary enzyme; less specific than lipase for pancreatitis.

Screening test for systemic autoimmune disease — high sensitivity, low specificity.

Highly specific for SLE; titers track lupus nephritis activity.

Acute-phase complement proteins; consumed in immune-complex disease.

IgM autoantibody against IgG Fc; sensitive but not specific for RA.

Highly specific for rheumatoid arthritis; predicts erosive disease.

First-line celiac disease serology; high sensitivity and specificity on a gluten-containing diet.

Glycoprotein from prostate epithelium; screening, surveillance, and post-treatment monitoring.

Mucin-16 epitope; ovarian cancer surveillance, NOT a screening test.

Oncofetal glycoprotein; colorectal cancer surveillance.

Fetal albumin; HCC and germ-cell tumor surveillance.

Sialyl-Lewis A antigen; pancreaticobiliary cancer marker.

Marker of active HBV infection (acute or chronic).

HCV exposure marker; reflex to HCV RNA to confirm active infection.

Detects p24 antigen + antibodies; window period ~2–4 weeks.

Bedside semi-quantitative screen of pH, specific gravity, protein, glucose, ketones, blood, leukocyte esterase, nitrites.

Microscopic exam of urine sediment — casts, crystals, cells.