Lab Tests & Biomarkers — Complete Reference Guide

This visual reference helps you understand the most commonly ordered annual lab tests at a glance. Each marker includes a color-coded range bar showing where low, normal, and high values fall so you can quickly interpret your results and have more informed conversations with your doctor.


Table of Contents

1. Complete Blood Count (CBC) 2. Comprehensive Metabolic Panel (CMP) 3. Lipid Panel 4. Thyroid Panel 5. Iron Panel 6. Diabetes Markers 7. Inflammatory Markers 8. Hormone Panel 9. Vitamins & Minerals 10. Urinalysis 11. Coagulation 12. Other Important Tests

How to Read the Range Bars

RED = LOW (below normal) GREEN = NORMAL (reference range) BLUE = OPTIMAL (functional/optimal) ORANGE = HIGH (above normal)

Each bar is divided into segments representing where your result falls. The numbers on each segment show the threshold values. Ranges shown are standard adult reference ranges; your lab may use slightly different values.


Complete Blood Count (CBC)

The CBC is the most frequently ordered blood test. It evaluates red blood cells, white blood cells, and platelets to detect infections, anemia, clotting disorders, and immune system conditions.

WBC — White Blood Cells (×10³/µL)

LOW < 4.0
NORMAL 4.0 — 11.0
HIGH > 11.0

RBC — Red Blood Cells, Male (×10⁶/µL)

LOW < 4.5
NORMAL 4.5 — 5.5
HIGH > 5.5

RBC — Red Blood Cells, Female (×10⁶/µL)

LOW < 4.0
NORMAL 4.0 — 5.0
HIGH > 5.0

Hemoglobin, Male (g/dL)

LOW < 13.5
NORMAL 13.5 — 17.5
HIGH > 17.5

Hemoglobin, Female (g/dL)

LOW < 12.0
NORMAL 12.0 — 16.0
HIGH > 16.0

Hematocrit, Male (%)

LOW < 38
NORMAL 38 — 50
HIGH > 50

Hematocrit, Female (%)

LOW < 36
NORMAL 36 — 44
HIGH > 44

Platelets (×10³/µL)

LOW < 150
NORMAL 150 — 400
HIGH > 400

MCV — Mean Corpuscular Volume (fL)

LOW < 80
NORMAL 80 — 100
HIGH > 100

Comprehensive Metabolic Panel (CMP)

The CMP is a group of 14 tests that evaluate kidney function, liver function, electrolyte balance, and blood sugar — providing a broad overview of your body's chemical balance and metabolism.

Glucose, Fasting (mg/dL)

LOW < 70
NORMAL 70 — 100
HIGH > 100

BUN — Blood Urea Nitrogen (mg/dL)

LOW < 7
NORMAL 7 — 20
HIGH > 20

Creatinine (mg/dL)

LOW < 0.6
NORMAL 0.6 — 1.2
HIGH > 1.2

eGFR — Estimated Glomerular Filtration Rate (mL/min)

LOW < 60
NORMAL ≥ 60

Sodium (mEq/L)

LOW < 136
NORMAL 136 — 145
HIGH > 145

Potassium (mEq/L)

LOW < 3.5
NORMAL 3.5 — 5.0
HIGH > 5.0

Calcium (mg/dL)

LOW < 8.5
NORMAL 8.5 — 10.5
HIGH > 10.5

Albumin (g/dL)

LOW < 3.5
NORMAL 3.5 — 5.0
HIGH > 5.0

Total Protein (g/dL)

LOW < 6.0
NORMAL 6.0 — 8.3
HIGH > 8.3

ALT — Alanine Aminotransferase (U/L)

NORMAL 7 — 56
HIGH > 56

AST — Aspartate Aminotransferase (U/L)

NORMAL 10 — 40
HIGH > 40

ALP — Alkaline Phosphatase (U/L)

LOW < 44
NORMAL 44 — 147
HIGH > 147

Bilirubin, Total (mg/dL)

NORMAL 0.1 — 1.2
HIGH > 1.2

Lipid Panel

The lipid panel measures fats and fatty substances in the blood to assess cardiovascular disease risk. It is one of the most important screening tests for heart health.

Total Cholesterol (mg/dL)

NORMAL < 200
BORDERLINE 200 — 239
HIGH > 240

LDL Cholesterol (mg/dL)

OPTIMAL < 100
NEAR OPTIMAL 100 — 129
HIGH > 130

HDL Cholesterol (mg/dL)

LOW < 40
NORMAL 40 — 60
OPTIMAL > 60

Triglycerides (mg/dL)

NORMAL < 150
BORDERLINE 150 — 199
HIGH > 200

VLDL Cholesterol (mg/dL)

NORMAL 2 — 30
HIGH > 30

Thyroid Panel

The thyroid panel evaluates how well your thyroid gland is functioning. Thyroid hormones regulate metabolism, energy, body temperature, heart rate, and many other vital processes.

TSH — Thyroid-Stimulating Hormone (mIU/L)

LOW < 0.4
NORMAL 0.4 — 4.0
HIGH > 4.0

Free T4 — Thyroxine (ng/dL)

LOW < 0.8
NORMAL 0.8 — 1.8
HIGH > 1.8

Free T3 — Triiodothyronine (pg/mL)

LOW < 2.3
NORMAL 2.3 — 4.2
HIGH > 4.2

Iron Panel

The iron panel measures how much iron is in your blood and how well your body stores and transports it. Iron is essential for oxygen delivery, energy production, and immune function.

Serum Iron (µg/dL)

LOW < 60
NORMAL 60 — 170
HIGH > 170

Ferritin, Male (ng/mL)

LOW < 30
NORMAL 30 — 400
HIGH > 400

Ferritin, Female (ng/mL)

LOW < 20
NORMAL 20 — 200
HIGH > 200

TIBC — Total Iron-Binding Capacity (µg/dL)

LOW < 250
NORMAL 250 — 370
HIGH > 370

Transferrin Saturation (%)

LOW < 20
NORMAL 20 — 50
HIGH > 50

Diabetes Markers

These markers assess blood sugar regulation and diabetes risk. HbA1c reflects your average blood sugar over the past 2-3 months, while fasting glucose and insulin provide a snapshot of current metabolic status.

HbA1c — Hemoglobin A1c (%)

NORMAL < 5.7
PREDIABETES 5.7 — 6.4
DIABETES > 6.5

Fasting Glucose (mg/dL)

NORMAL < 100
PREDIABETES 100 — 125
DIABETES > 126

Fasting Insulin (µIU/mL)

LOW < 2
NORMAL 2 — 20
HIGH > 20

Inflammatory Markers

Chronic low-grade inflammation is linked to heart disease, cancer, diabetes, and autoimmune conditions. These tests help identify hidden inflammation before it progresses to serious disease.

hs-CRP — High-Sensitivity C-Reactive Protein (mg/L)

LOW RISK < 1.0
AVERAGE 1.0 — 3.0
HIGH RISK > 3.0

ESR, Male — Erythrocyte Sedimentation Rate (mm/hr)

NORMAL 0 — 15
MILD 15 — 20
HIGH > 20

ESR, Female — Erythrocyte Sedimentation Rate (mm/hr)

NORMAL 0 — 20
MILD 20 — 30
HIGH > 30

Homocysteine (µmol/L)

NORMAL < 10
ELEVATED 10 — 15
HIGH > 15

Hormone Panel

Hormones regulate virtually every process in your body — from energy and mood to reproductive health and body composition. Imbalances can cause fatigue, weight gain, depression, and many other symptoms.

Testosterone, Male (ng/dL)

LOW < 300
NORMAL 300 — 1000
HIGH > 1000

Testosterone, Female (ng/dL)

LOW < 15
NORMAL 15 — 70
HIGH > 70

Estradiol, Premenopausal (pg/mL)

LOW < 30
NORMAL 30 — 400
HIGH > 400

Cortisol, Morning (µg/dL)

LOW < 6
NORMAL 6 — 23
HIGH > 23

DHEA-S, Male (µg/dL)

LOW < 80
NORMAL 80 — 560
HIGH > 560

DHEA-S, Female (µg/dL)

LOW < 35
NORMAL 35 — 430
HIGH > 430

Vitamins & Minerals

Nutrient deficiencies are surprisingly common and can cause wide-ranging symptoms — from fatigue and brain fog to nerve damage and bone loss. These tests identify the most critical nutritional gaps.

Vitamin D (25-OH) (ng/mL)

DEFICIENT < 20
INSUFFICIENT 20 — 29
NORMAL 30 — 100

Vitamin B12 (pg/mL)

LOW < 200
NORMAL 200 — 900
HIGH > 900

Folate (ng/mL)

LOW < 3
NORMAL 3 — 20
HIGH > 20

Magnesium (mg/dL)

LOW < 1.7
NORMAL 1.7 — 2.2
HIGH > 2.2

Urinalysis

A urinalysis checks the appearance, concentration, and content of urine. It can detect kidney disease, urinary tract infections, diabetes, and other metabolic conditions.

pH

ACIDIC < 5.0
NORMAL 5.0 — 8.0
ALKALINE > 8.0

Specific Gravity

LOW < 1.005
NORMAL 1.005 — 1.030
HIGH > 1.030

Protein

NORMAL — Negative
ABNORMAL — Positive

Glucose

NORMAL — Negative
ABNORMAL — Positive

Coagulation Panel

Coagulation tests measure how well your blood clots. They are essential before surgeries, for monitoring blood-thinning medications, and for diagnosing bleeding or clotting disorders.

PT — Prothrombin Time (seconds)

LOW < 11
NORMAL 11 — 13.5
HIGH > 13.5

INR — International Normalized Ratio (therapeutic on warfarin: 2.0–3.0)

LOW < 0.8
NORMAL 0.8 — 1.1
HIGH > 1.1

aPTT — Activated Partial Thromboplastin Time (seconds)

LOW < 25
NORMAL 25 — 35
HIGH > 35

Other Important Tests

These additional tests are frequently ordered during annual physicals and can reveal conditions such as gout, liver dysfunction, and prostate issues.

Uric Acid, Male (mg/dL)

LOW < 3.5
NORMAL 3.5 — 7.2
HIGH > 7.2

Uric Acid, Female (mg/dL)

LOW < 2.5
NORMAL 2.5 — 6.0
HIGH > 6.0

GGT — Gamma-Glutamyl Transferase (U/L)

NORMAL 0 — 51
ELEVATED > 51

PSA — Prostate-Specific Antigen, Male (ng/mL)

NORMAL < 4.0
ELEVATED > 4.0

Conventional vs. Functional/Optimal Ranges

Most lab reports use conventional reference ranges that are derived from population averages — which include many unhealthy individuals. Functional medicine practitioners often use narrower, optimal ranges based on healthy populations and peer-reviewed research. For example, a conventional TSH range might be 0.4–4.0, while a functional optimal range is 1.0–2.5. Similarly, conventional fasting glucose of 65–99 may be considered normal, but functional practitioners prefer 75–86.

If your results fall within conventional ranges but you still experience symptoms, consider asking your provider about functional/optimal ranges — early intervention at the "sub-optimal" stage can prevent progression to diagnosable disease.


IMPORTANT DISCLAIMER: This page is an educational reference to help you understand your lab results. It does NOT replace professional medical interpretation. Reference ranges may vary between laboratories. Always discuss your results with a qualified healthcare provider who can consider your complete health picture, symptoms, medications, and medical history.

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