Translate Your Blood Test Results

Your report uses abbreviations and reference ranges that most labs never explain. Here's what each one means, in plain English.

Written by Ankit Agarwal·Published
40+ common abbreviations decoded What H and L flags mean How to spot patterns that matter

Blood test abbreviations fall into two main panels: a CBC (complete blood count) measures your blood cells — RBC, WBC, HGB, HCT, MCV, MCH, MCHC, RDW, and platelets. A metabolic panel measures organ function and chemistry — glucose, BUN, creatinine, eGFR, ALT, AST, albumin, and electrolytes. An H next to a result means above the reference range; L means below. One flag alone is rarely the full story — the pattern across related markers is what points to a root cause.

Complete blood count (CBC) — abbreviations decoded

The CBC is the most common blood test. It measures how many cells of each type are in your blood and what shape they are.

Abbreviation Full name What it measures When it's flagged
WBC White blood cell count Total number of immune cells in your blood High: infection, inflammation, stress. Low: bone marrow issues, some medications
RBC Red blood cell count Number of oxygen-carrying red cells Low: anaemia. High: dehydration, polycythaemia
HGB / HB Haemoglobin Protein inside red cells that carries oxygen Low: anaemia from iron deficiency, B12 deficiency, chronic disease
HCT / PCV Haematocrit / Packed cell volume Percentage of blood volume that is red cells Moves with HGB — low = anaemia, high = dehydration or polycythaemia
MCV Mean corpuscular volume Average size of your red blood cells Low: iron deficiency. High: B12 or folate deficiency, liver disease, alcohol
MCH Mean corpuscular haemoglobin Average amount of haemoglobin per red cell Follows MCV pattern — low with iron deficiency, high with B12/folate deficiency
MCHC Mean corpuscular haemoglobin concentration Concentration of haemoglobin in each red cell Low: iron deficiency anaemia. High: hereditary spherocytosis (rare)
RDW Red cell distribution width How varied in size your red cells are High: iron deficiency, B12 deficiency, mixed anaemia — red cells are uneven in size
PLT Platelet count Number of clotting particles in your blood Low: bleeding risk, certain infections. High: inflammation, iron deficiency, infection
NEUT / NEU Neutrophils Most common white cell — first responder to bacterial infection High: bacterial infection, stress. Low: viral infection, some drugs
LYMPH Lymphocytes White cells that drive immune memory and virus response High: viral infections, CLL. Low: some autoimmune conditions, HIV
MONO Monocytes White cells that clean up debris and signal inflammation High: chronic inflammation, infection, some autoimmune conditions
EOS Eosinophils White cells involved in allergy and parasite response High: allergies, asthma, parasitic infection, drug reactions
BASO Basophils Least common white cell — involved in allergic response Borderline high is often statistical variation. Persistently high: thyroid or bone marrow issues

Metabolic panel — abbreviations decoded

A basic metabolic panel (BMP) covers 8 markers. A comprehensive metabolic panel (CMP) adds liver markers and protein. Together they cover kidney function, blood sugar, electrolytes, and liver health.

Abbreviation Full name What it measures When it's flagged
Blood sugar
GLU / GLUC Glucose Blood sugar at time of draw High (fasting): diabetes or prediabetes. High (non-fasting): expected after eating
Kidney function
BUN Blood urea nitrogen Waste product the kidney filters out High: dehydration, kidney stress, high-protein diet. Low: liver disease, low protein intake
CREAT / CR Creatinine Muscle waste product cleared by the kidneys High: kidney impairment, dehydration, high muscle mass. See also high creatinine
eGFR Estimated glomerular filtration rate Estimated kidney filtration capacity (calculated from creatinine + age + sex) Below 60: reduced kidney function. Below 15: severe impairment requiring specialist care
Electrolytes
NA / SOD Sodium Key electrolyte controlling fluid balance High or low: dehydration, medication side effects, kidney or adrenal issues
K / POT Potassium Electrolyte critical for heart and muscle function Critically high or low: cardiac risk. Often affected by medications (diuretics, ACE inhibitors)
CL / CHLOR Chloride Electrolyte; follows sodium in most cases Rarely flagged in isolation; usually read alongside sodium and bicarbonate
CO2 / BICARB Carbon dioxide / Bicarbonate Measures the acid-base balance of blood Low: acidosis (kidney issues, diabetic ketoacidosis). High: alkalosis (vomiting, diuretics)
Liver function (CMP only)
ALT / SGPT Alanine aminotransferase Enzyme released when liver cells are damaged High: liver stress or damage. More liver-specific than AST. See liver function guide
AST / SGOT Aspartate aminotransferase Enzyme from liver and muscle; rises with damage to either High: liver disease, muscle injury, heavy exercise, alcohol. Less specific than ALT
ALP / ALKP Alkaline phosphatase Enzyme from liver, bone, and bile ducts High: bile duct blockage, bone disease, liver disease. Elevated in growing children (normal)
TBIL / T.BILI Total bilirubin Breakdown product of red blood cells; cleared by the liver High: liver disease, haemolysis (red cell breakdown), bile duct obstruction
ALB Albumin Protein made by the liver; reflects nutritional status and liver function Low: liver disease, malnutrition, inflammation, kidney protein loss
TP / TPROT Total protein Sum of albumin and globulin proteins in blood Low: malnutrition, liver disease. High: dehydration, certain immune conditions

Other common panels and abbreviations

Beyond the CBC and metabolic panel, most reports include lipids, thyroid, and often a selection of vitamins and hormones.

Abbreviation Full name What it measures Learn more
Lipid panel (cholesterol)
TC / CHOL Total cholesterol All cholesterol types combined Lipid panel guide
LDL Low-density lipoprotein "Bad" cholesterol — deposits in artery walls High LDL guide
HDL High-density lipoprotein "Good" cholesterol — removes LDL from circulation Lipid panel guide
TG / TRIG Triglycerides Blood fats; rise with excess carbohydrates, alcohol, and metabolic dysfunction High triglycerides guide
Thyroid
TSH Thyroid-stimulating hormone Pituitary signal to the thyroid — high TSH means the thyroid is underperforming TSH guide
FT4 / FREE T4 Free thyroxine Active thyroid hormone available to the body TSH guide
Iron and nutrition
FERR / FERRITIN Ferritin Iron storage protein — the earliest indicator of iron depletion Low ferritin guide
TSAT Transferrin saturation Percentage of iron-transport protein that is carrying iron Low ferritin guide
25-OH VIT D / VIT D 25-hydroxyvitamin D The storage form of vitamin D — the standard test for deficiency Low vitamin D guide
B12 / COBAL Vitamin B12 / Cobalamin Essential for red cell production and nerve function Low B12 guide
Inflammation
CRP / hsCRP C-reactive protein Acute-phase inflammatory marker; hsCRP is the high-sensitivity version CRP guide
HbA1c / A1C Glycated haemoglobin Average blood sugar over the past 2–3 months HbA1c guide

What H and L flags actually mean

A flag is a starting point, not a verdict. Here's how to read the weight behind one.

Reference ranges are population statistics

Labs set reference ranges to cover the middle 95% of results from a healthy reference group. That means 1 in 20 healthy people will land outside the range on any given test — by design, not disease. On a 20-marker panel, a healthy person has a 64% chance of at least one flag.

Magnitude matters

A creatinine of 1.9 against an upper limit of 1.2 is not the same as one barely touching 1.21. Both get an H flag. The distance from the boundary — not the flag itself — tells you how much weight to put on it.

Pattern beats single flags

Low ferritin + low MCV + low MCH is not three problems — it's one iron deficiency showing up across three related tests. Scattered flags from unrelated systems with no symptom match are usually statistical noise rather than a cluster pointing to a root cause.

Multiple flags?
See how to tell which ones cluster into a single root cause versus which are independent statistical variation.
Multiple abnormal results: what they actually mean

Common patterns and what they point to

Multiple related flags usually trace to one root cause. These are the four most common clusters on a standard panel.

🩸 Iron deficiency
Low ferritin · Low MCV · Low MCH · Low HGB
Iron depletes in stages. Ferritin (storage) drops first, then MCV and MCH (red cell size and haemoglobin content), then haemoglobin itself. Four flags from one cause — treating iron typically brings all four back in range. See the low ferritin guide.
🦋 Hypothyroidism
High TSH · High LDL · Elevated CK
Thyroid hormones regulate cholesterol metabolism and muscle function. An underactive thyroid simultaneously pushes TSH up, raises LDL, and can elevate CK. Three flags, three different panels, one upstream cause. See the TSH guide.
🔬 B12 or folate deficiency
High MCV · High MCH · Low B12 or folate
B12 and folate are required for normal red cell maturation. Deficiency of either causes large, abnormal red cells — elevated MCV and MCH. Two CBC flags that point to one nutritional gap. See the low B12 guide.
⚡ Acute inflammation
Elevated CRP · Elevated WBC · Elevated ferritin
After infection, surgery, or significant physical stress, CRP, WBC, and ferritin all rise together as part of the inflammatory response. These flags reflect the response to illness, not separate diseases. They typically normalise within 2–4 weeks of recovery.

Can AI interpret my blood test results?

AI tools can translate abbreviations, explain what each marker measures, flag values outside the reference range, and identify common patterns across multiple results — which most lab reports don't do. What AI can't do is replace a clinical diagnosis, which requires your medical history, symptoms, and physical examination.

The practical use case: AI is best for understanding your results before or between appointments — so you arrive knowing what questions to ask, rather than spending the appointment decoding what the abbreviations mean. For any result your lab has flagged as critically high or critically low, contact your doctor directly rather than relying on any automated interpretation.

Note: This guide covers the most common blood test abbreviations. Your own lab's reference ranges are the authority for your results — ranges vary by lab, age, sex, and testing method. This is educational information, not medical advice.

Frequently asked questions

How do I translate my blood test results?
Start with the panel: a CBC measures blood cell counts (RBC, WBC, HGB, HCT, MCV, MCH, MCHC, RDW, and platelets). A metabolic panel measures organ function and chemistry (glucose, BUN, creatinine, eGFR, ALT, AST, albumin, and electrolytes). H next to a result means above the reference range; L means below. One flag alone is usually not serious — the pattern across related markers is what points to a root cause.
What does H and L mean on blood test results?
H means the value is above the lab's reference range. L means below. Reference ranges are set to cover the middle 95% of a healthy population, so 1 in 20 healthy people will land outside the range on any given test by statistical design alone. A borderline H or L with no matching symptoms is often statistical variation. A value significantly outside the range, or one that clusters with other related flags, carries more weight.
What are red flags on a blood test?
True red flags are values significantly outside the reference range in markers tied to organ function: creatinine or eGFR indicating acute kidney impairment, ALT or AST at 3× or more the upper limit (acute liver stress), critically abnormal sodium or potassium, haemoglobin below 8 g/dL, or white blood cell counts at extremes alongside symptoms. A borderline H on a single marker with no symptoms is low priority. Severity plus clinical pattern determines urgency.
Can AI interpret my blood results?
Yes — AI tools can translate abbreviations, explain what each marker measures, identify flagged values, and spot common patterns across multiple results. What they can't do is replace a clinical diagnosis, which requires your medical history, symptoms, and physical examination. AI is best used to understand what you're looking at before or between doctor appointments, not as a substitute for one.
What app interprets blood test results?
FixFirst lets you upload any blood test report (PDF or photo) and returns a ranked interpretation of every marker — what each value means, which flags are clinically significant vs. statistical noise, and what to discuss with your doctor. It covers 156 markers including the CBC, metabolic panel, lipid panel, thyroid, iron studies, and vitamins. No account required.
What blood tests check liver function?
A standard liver function test (LFT) includes ALT, AST, ALP, total bilirubin, albumin, and total protein. ALT is the most liver-specific marker — a rise here usually reflects liver cell damage rather than muscle or bone. AST rises in both liver and muscle injury. ALP is more specific to bile ducts and bone. Bilirubin rises when the liver can't clear the breakdown products of red blood cells. See the liver function blood test guide for full reference ranges.

Upload your report and see what to fix first

FixFirst reads your actual values, ranks every flagged marker by clinical weight, and shows you the pattern — not just a colour-coded list of H and L. Free, no account needed.

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