Lab results abbreviations, explained in plain words

Frequently asked questions

• 01What do H and L mean on a blood test?

  “H” usually means your result is higher than the reference range printed on the report, and “L” means lower. Some labs use arrows (↑ ↓) or words like “High” and “Low” instead, and a double letter (HH, LL) or an asterisk often marks a critical value, which the lab reports to the ordering clinician right away. A flag only tells you where your number sits against that lab’s range; it isn’t a diagnosis. About 1 in 20 healthy people land outside a typical range by chance, so a single flag is something to discuss with your clinician, not to decode alone. Astras carries the printed flag into each row.

• 02What does "abs" or "#" mean next to neutrophils or lymphocytes?

  “Abs” or “#” is the absolute count: how many cells of that type are in a set volume of blood. The percentage next to it is that type’s share of all your white cells. Both come from the same sample, but each has its own reference range, so one can be flagged while the other isn’t. Because the percentages of all white cell types add up to 100, one type’s share also moves when another type’s count changes. Read each number against its own range, and look at the total WBC too. The unit tells you which is which: “%” for the share, a count unit like K/µL or 10⁹/L for the absolute number.

• 03Why is my reference range different from another lab’s?

  Because each lab sets or checks its ranges for its own instruments, reagents and methods, and for its own reference group of healthy people. Ranges can also differ by age, sex and pregnancy, and the same result looks different in another unit (mg/dL versus mmol/L, for example). That’s why a value inside the range at one lab can be flagged at another. The practical rule: compare your result only with the range printed next to it on the same report, and stay with one lab for trends when you can. Astras follows the same rule and never applies a range from elsewhere.

• 04Why doesn’t this page list normal values?

  Because there’s no single set of normal values that fits every lab. A number taken from a generic table can contradict the range your own lab printed, and that range was built for the exact method used on your sample. Astras is built on this principle: every range comes from your report, and nothing is recalculated. This page tells you what each abbreviation means; the report tells you where your number sits. If a report prints no range for a row, Astras marks it “not assessed” instead of filling in a number from somewhere else.

• 05What’s the difference between HGB and HbA1c?

  They’re different tests that both contain the word hemoglobin. HGB (Hgb, Hb) on a complete blood count is how much hemoglobin, the oxygen-carrying protein in red cells, is in your blood. HbA1c (A1C) shows how much of that hemoglobin has glucose attached, which reflects your average blood sugar over about the past three months. They have different units (HGB is a concentration such as g/dL; HbA1c in the US is a percentage) and different ranges, and they appear on different parts of a report. Astras keeps them as separate markers.

• 06What do SGPT and SGOT mean on my report?

  They’re older names for ALT and AST, two enzymes on a comprehensive metabolic panel. SGPT (also GPT) is alanine aminotransferase, an enzyme found mostly in the liver. SGOT (also GOT) is aspartate aminotransferase, found mainly in the liver but also in the heart, muscles and other tissues. Some labs still print the older names, so a report with “GPT” and one with “ALT” can show the same test. When you upload reports to Astras, names from different labs for the same marker are merged into one history whenever the match is clear.

• 07What does "calculated" mean next to LDL or eGFR?

  It means the lab worked the value out from other results instead of measuring it directly. A calculated LDL-C is estimated from total cholesterol, HDL and triglycerides; a “direct” LDL is measured from the sample. eGFR is always an estimate, calculated from creatinine (sometimes cystatin C) and details such as age and sex. Non-HDL cholesterol (total minus HDL) and transferrin saturation are calculated too. A calculated value can differ from a measured one, so when you compare reports, check which kind each one is. Astras copies the value as printed and doesn’t recalculate it.

• 08Can Astras explain the abbreviations on my own report?

  Yes. Upload a photo or PDF and every row is copied as printed: name, value, unit, range and date. You check each line before anything is saved. Codes like TSH, WBC or eGFR stay as printed so you can match them with the paper, and the marker name appears in your app language, even when the report is in another language. Tap any marker for its card: your value against the report’s range and, for over 130 common markers, a plain-language article. Your saved results stay free to view; reading new reports is part of a plan. Start at lab results explained.