| name | Bloodwork Explainer |
| description | Explains common lab panels in plain language and what questions to bring to a doctor. Use when reviewing blood test results and wanting to understand what markers mean. Education only; not medical advice or diagnosis. |
Bloodwork Explainer
This skill translates common blood test results into plain language and helps formulate informed questions for a physician. It does not diagnose conditions or recommend treatments. Lab interpretation is always context-dependent — age, sex, medications, and symptoms matter. Bring all questions to a qualified healthcare provider.
Complete Blood Count (CBC)
The CBC measures red blood cells (RBCs), white blood cells (WBCs), and platelets. Key markers: hemoglobin (oxygen-carrying capacity; low suggests anemia), hematocrit (percentage of blood that is RBCs), WBC count (immune activity; high can indicate infection or inflammation), and platelets (clotting). A single out-of-range value in isolation rarely means much — trends and clinical context matter.
Comprehensive Metabolic Panel (CMP)
The CMP screens organ function. Liver markers: ALT and AST (elevated with liver stress, heavy alcohol, or intense exercise); ALP (bile ducts and bone). Kidney markers: creatinine and BUN (waste clearance); eGFR (estimated kidney filtration rate). Electrolytes: sodium, potassium, chloride, bicarbonate. Glucose (fasting): normal is 70–99 mg/dL; 100–125 is pre-diabetic range. Calcium: relevant for bone and nerve function.
Lipid Panel
Measures cardiovascular risk markers. Total cholesterol alone is a poor predictor. Focus on: LDL (low-density lipoprotein — the primary target; optimal is generally under 100 mg/dL for most adults, lower for high-risk individuals), HDL (high-density lipoprotein — higher is better; under 40 mg/dL is a risk factor), and triglycerides (under 150 mg/dL is normal; high levels correlate with poor metabolic health). Ask the doctor about ApoB if cardiovascular risk is a concern.
Hormones and Thyroid
TSH (thyroid-stimulating hormone) is the standard thyroid screen; abnormal values prompt follow-up with free T4 and T3. Testosterone (total and free) is relevant for symptoms of fatigue, low libido, or body composition changes in both men and women. HbA1c reflects average blood glucose over roughly 3 months and is the standard diabetes screen. Vitamin D (25-OH) is frequently low; optimal range is debated but most clinicians target 30–60 ng/mL.
What to Ask Your Doctor
Useful questions: What is the trend versus my previous results? Which out-of-range values require action now versus monitoring? Are any medications or supplements affecting these results? What lifestyle changes would move the most important markers? When should I retest?
Understanding Reference Ranges
Reference ranges are statistical, not absolute — they represent the middle 95% of a tested population, which includes undiagnosed sick people. Optimal ranges for longevity sometimes differ from standard lab reference ranges. Never self-diagnose from a single panel. Use results as a starting point for a productive conversation with a doctor.
