Lab results, explained

One number on a lab report rarely tells the whole story. Pick a marker below for a plain-language guide — the normal range, what high and low mean, common causes, and when it’s worth following up. Then analyze your full report, free and anonymously.

Blood count

• Hemoglobin →12–17.5 g/dL
  Hemoglobin is the protein in red blood cells that carries oxygen — low hemoglobin defines anemia.

Metabolic

• Hemoglobin A1c →4–5.6 %
  HbA1c reflects your average blood sugar over roughly the past three months — the standard test for diagnosing and monitoring diabetes.

Lipids

• LDL Cholesterol →0–100 mg/dL
  LDL cholesterol — often called "bad" cholesterol — is the lipid fraction most directly linked to plaque buildup and cardiovascular risk.
• HDL Cholesterol →40–80 mg/dL
  HDL cholesterol — the "good" cholesterol — helps clear cholesterol from the arteries, so higher levels are generally protective.
• Triglycerides →0–150 mg/dL
  Triglycerides are the most common type of fat in the blood and a marker of how your body handles dietary fat and sugar.

Liver & kidney

• ALT (Alanine Aminotransferase) →7–55 U/L
  ALT is a liver enzyme released into the blood when liver cells are stressed or damaged — one of the most sensitive markers of liver health.
• AST (Aspartate Aminotransferase) →8–48 U/L
  AST is an enzyme found in the liver, heart, and muscles; in routine testing it is used mainly to assess liver health alongside ALT.
• Creatinine →0.7–1.3 mg/dL
  Creatinine is a muscle waste product cleared by the kidneys — the standard blood marker used to estimate kidney function.

Thyroid

• TSH (Thyroid-Stimulating Hormone) →0.4–4 mIU/L
  TSH is the pituitary hormone that tells your thyroid how hard to work — it is the primary screening test for thyroid function.

Vitamins & iron

• Ferritin →30–300 ng/mL
  Ferritin is the protein that stores iron in your body — it is the single best blood marker of how much iron you have in reserve.
• Vitamin D (25-Hydroxyvitamin D) →30–80 ng/mL
  The 25-hydroxyvitamin D test is the standard measure of your vitamin D status, reflecting both sun exposure and dietary intake.
• Vitamin B12 →200–900 pg/mL
  Vitamin B12 is essential for nerve function and red-blood-cell formation — a deficiency can cause anemia and neurological symptoms.

Inflammation

• CRP (C-Reactive Protein) →0–3 mg/L
  CRP is a protein made by the liver that rises with inflammation anywhere in the body — a general marker of inflammatory activity.