Read a lab report in this order: confirm whose report it is and when the sample was collected, find the full test name, read the value with its unit, read the reference range printed on that same report, check the flag and any remarks, then compare the value with your earlier results. Doctano does the last step by keeping every result on a timeline and linking each one to its source.
Before you read a number
The first page of a lab report is mostly context, and four details tell you whether you are reading the right document.
- Whose report it is. The name and date of birth should match the person you are reading for.
- When the sample was collected. This is not always the same as the report date.
- Which lab produced it. The lab determines the method and the reference range.
- Which page you are on. Long reports repeat panels across pages, and a value can appear twice.
Step 1: confirm the person and the dates
The collection date is when the sample was taken. The report date is when the result was released. They are often a day or two apart. A value from last Tuesday and a value from last year are not the same kind of information.
If the dates look wrong, or the report has two dates that are weeks apart, ask the lab before treating the result as current.
Step 2: read the full test name
Abbreviations are where most of the confusion lives. SGOT is AST, SGPT is ALT, PCV is haematocrit, and TLC is the total white cell count. The report usually prints the full name beside the abbreviation, sometimes only once at the top of the panel.
Use the report's own expansion when it prints one. If it does not, our blood test abbreviations guide covers the common codes, including calculated indices that many lists skip.
Step 3: keep the value attached to its unit
A glucose of 99 means nothing until you know whether the unit is mg/dL or mmol/L. The same number in the two units describes very different states. Read the unit column before you decide whether a value is high or low.
The same rule applies across reports. If one lab reports cholesterol in mg/dL and another in mmol/L, the numbers will look unrelated even when the result is similar.
Step 4: use the range printed on that report
The reference range belongs to the lab, the method, and often the age and sex on the report. A chart from the internet cannot know any of that. The range on the page is the one that applies to the value on the page.
Some reports print a target rather than a population range, especially for LDL cholesterol. A target and a reference range are not the same thing. Our reference ranges guide explains the difference.
Step 5: look at the flag and the remarks
H and L, or High and Low, are the lab's own comparison against its range. They are useful, but they are not a diagnosis, and a report can carry no flag simply because the lab does not flag that test.
Below the result, a remark can change how much weight to give it: sample hemolysed, fasting status not confirmed, test repeated, sample diluted. A value produced from a compromised sample is still a value, but it is a weaker one.
Step 6: read the values as a panel, not a list
Some markers are only meaningful together: ALT with AST, urea with creatinine, TSH with free T4, LDL with triglycerides. A page of isolated numbers hides the pattern that a panel makes visible. For a panel-by-panel walkthrough, see the panel pages; for one result in detail, see the test pages.
Step 7: compare with your own history
The most useful comparison is not against the population range. It is against your last result, from a comparable lab, under comparable conditions. One reading is a data point; three readings are a direction.
Doctano keeps each marker's values across reports and links every value back to the report it came from, so this step does not depend on a folder of PDFs or a spreadsheet you have to maintain.
A worked example
Here is a fictional excerpt, laid out the way many labs print one.
| Test | Result | Unit | Reference | Flag |
|---|---|---|---|---|
| Haemoglobin | 13.4 | g/dL | 13.0-17.0 | Normal |
| Fasting glucose | 104 | mg/dL | 70-99 | High |
| HbA1c | 5.9 | % | 4.0-5.6 | High |
| LDL cholesterol | 128 | mg/dL | Below 100 | High |
| TSH | 2.1 | uIU/mL | 0.4-4.0 | Normal |
| Vitamin D (25-OH) | 18 | ng/mL | 30-100 | Low |
Read in order, this is two results inside their ranges, four flags, and one pattern worth taking to a doctor: a fasting glucose and HbA1c just above the lab's limits, an LDL above the printed target, and a vitamin D below its range. None of that is a diagnosis. It is a list of questions for the next conversation, checked against your previous report.
What the report cannot tell you
- Whether a value is a trend or a one-off. That needs earlier results.
- Why it changed. A number does not carry a cause.
- What to do about it. That depends on your history, symptoms, medicines, and examination.
- Whether the sample was representative. That is what the remarks are for.
Those questions need your history and a qualified professional. A report is evidence, not a plan.