How to track your cholesterol over time
A lipid panel is one of the most ordered blood tests there is. Most adults have had several, usually years apart and often at different clinics or labs. Each one gets a glance at the time, but read on its own, a single panel says little about where your cholesterol is heading. Ten years of panels on one chart show whether your LDL has been creeping up, whether a statin did what it was supposed to, and whether last spring’s high triglycerides were a pattern or a one-off.
What a lipid panel measures
A standard lipid panel reports four numbers:
- Total cholesterol: all the cholesterol carried in your blood.
- LDL cholesterol: cholesterol carried in low-density lipoprotein, the particles most tied to plaque in the arteries. This is the number most treatment decisions are built on.
- HDL cholesterol: cholesterol carried in high-density lipoprotein, which moves cholesterol back to the liver.
- Triglycerides: a different kind of fat, which rises and falls with what you have eaten and drunk recently far more than cholesterol does.
Many reports add a few calculated lines:
- Non-HDL cholesterol is total cholesterol minus HDL. It counts the cholesterol in every particle that can build plaque, not only LDL, and it is not affected by whether you fasted.
- VLDL cholesterol is usually estimated from triglycerides, not measured.
- Total cholesterol / HDL ratio is just what it says.
None of these calculated values add information the four main numbers do not already contain. Non-HDL is still worth charting on its own, because the current guideline sets goals for it.
Calculated LDL and direct LDL
Most labs do not measure LDL. They calculate it from the other three numbers. The oldest method, the Friedewald equation from 1972, is:
LDL = total cholesterol − HDL − (triglycerides ÷ 5) (all in mg/dL)
It works well in the middle of the range and badly at the edges. When triglycerides are high, or when LDL is very low, as it often is on treatment, Friedewald tends to underestimate LDL. Above 400 mg/dL of triglycerides it is not used at all. Newer equations, from Martin and Hopkins and from the NIH (Sampson), hold up better in those cases, and many labs have switched to one of them. A lab can also measure LDL directly, which some report as “LDL Direct” or “Direct LDL”.
For tracking, the method matters more than it seems. If your lab switches equations, or a second lab uses a different one, your LDL can shift by several points with no change in your blood. The difference is largest at low LDL and high triglycerides, which is exactly where many people on treatment live. The method is usually printed on the report, in the test name or a footnote. Note it with the result. To see how far apart the equations land for your own numbers, enter a panel into the LDL cholesterol calculator.
The numbers on the report
Lipid “reference ranges” are unusual. For most tests, the range on the report describes healthy people. For cholesterol, it is a set of cutoffs borrowed from guidelines, which is why nearly every lab prints the same ones. The long-standing U.S. categories, still used by many labs and summarized by the NHLBI, are:
| Test (mg/dL) | Desirable | Borderline | High |
|---|---|---|---|
| Total cholesterol | Below 200 | 200 to 239 | 240 or above |
| LDL cholesterol | Below 100 | 130 to 159 | 160 or above |
| Triglycerides | Below 150 | 150 to 199 | 200 or above |
| HDL cholesterol | 60 or above is good | Below 40 (men), below 50 (women) is low |
LDL between 100 and 129 is often labeled “near optimal”, and 190 or above “very high”.
Those cutoffs are not the same as a treatment goal. The 2026 ACC/AHA dyslipidemia guideline, which replaced the 2018 cholesterol guideline in March, brought back LDL targets that depend on your overall risk: below 100 mg/dL for many people at borderline or intermediate risk, below 70 for high risk, and below 55 for some people who already have heart disease. Your clinician sets your goal from your risk, not from the lab’s column. If your goal is below 70, a report that flags only values above 130 will show “normal” on results you are trying to bring down.
mg/dL and mmol/L
Outside the United States, lipids are usually reported in mmol/L. A history that includes results from Canada, the UK, Europe, or Australia will mix the two, and the numbers are far apart: an LDL of 3.0 mmol/L is about 116 mg/dL. The conversion factors differ by test:
| Test | mmol/L to mg/dL |
|---|---|
| Total, LDL, HDL, non-HDL cholesterol | multiply by 38.67 |
| Triglycerides | multiply by 88.57 |
Convert everything to one unit before you chart it. A chart that mixes them will look like your cholesterol jumped by a factor of 39.
How often it is tested
Lipids are tested far less often than A1c, which makes each result count:
- Routine screening: every few years for most adults, starting in young adulthood. The 2026 guideline starts screening at age 19.
- After starting or changing a cholesterol medication: about 4 to 12 weeks later, to see how well it worked.
- On stable treatment: every 6 to 12 months.
Statins and most other LDL-lowering drugs act quickly. LDL settles at its new level within about a month, so the panel at 4 to 12 weeks shows most of the effect. That makes cholesterol one of the cleaner tests for a before-and-after, as long as you have a good “before”. Did the medication actually do anything? covers how to read one fairly.
Because routine screening happens every few years, a long history may have only a handful of points, spread across employers, insurers, and health systems. A panel from a job physical ten years ago may be your only baseline from before treatment. How to get all of your medical records covers tracking down the older ones.
What counts as a real change
Lipids vary from draw to draw in the same person even when nothing has changed. Studies of within-person variation put total and LDL cholesterol at roughly 5 to 10 percent from one draw to the next, and triglycerides at 20 percent or more. On an LDL of 130, a result anywhere from about 120 to 140 can be ordinary noise. Triglycerides can swing from 120 to 180 without meaning much.
A few questions help sort it out:
- Is the change bigger than your usual spread? If your last four LDL results ran from 118 to 134, a 128 is not news. A 160 is.
- Did the other numbers move the way they should? If LDL dropped but total cholesterol and non-HDL barely moved, look at the triglycerides and the LDL method before you believe it.
- Was anything unusual about the draw? See the next section.
Things that move your lipids
Some changes in a lipid panel have nothing to do with your long-term cholesterol.
- Fasting. Fasting is no longer required for most lipid panels. A 2016 European consensus found that after ordinary meals, triglycerides rise by about 26 mg/dL on average, while total and LDL cholesterol fall by about 8 mg/dL or less. That is small for cholesterol and meaningful for triglycerides. If your history mixes fasting and non-fasting draws, note which was which, and read the triglycerides with that in mind.
- Alcohol and a heavy meal the day before can push triglycerides well up.
- Recent illness, surgery, or a heart attack can lower cholesterol for weeks. A panel drawn in the hospital, or just after a bad infection, may read low.
- Pregnancy raises cholesterol and triglycerides substantially, especially later in pregnancy.
- An underactive thyroid raises LDL. If your LDL climbs without an obvious reason, a TSH result from around the same time is worth a look.
- Your menstrual cycle shifts cholesterol a little across the month. Your cycle shows up in your labs has the details.
- Weight change moves lipids, and so does any new medication on a long list that includes steroids, some blood pressure drugs, some HIV drugs, and isotretinoin.
None of these mean the result is wrong. They mean it needs a note next to it.
Lp(a) and ApoB
Two other tests show up more often now, and they behave differently over time.
Lipoprotein(a), or Lp(a), is mostly set by your genes. It barely changes with diet or exercise, so the 2026 guideline recommends measuring it once in every adult, and there is usually no reason to repeat it. For tracking, it is one value to keep, not a line to chart. One catch: Lp(a) is reported in either nmol/L or mg/dL, and there is no reliable conversion between them. The guideline’s threshold for elevated is 125 nmol/L or 50 mg/dL. Keep the unit with the number.
Apolipoprotein B, or ApoB, counts the particles that can build plaque rather than the cholesterol inside them. The guideline uses it selectively, mostly for people who have reached their LDL and non-HDL goals but still carry extra risk, such as from diabetes or high triglycerides. If you have several ApoB results, chart them like any other test. If you have one, keep it with the panel it came from.
What to record with each result
For each lipid panel, keep:
| Field | Why |
|---|---|
| Collection date | Lipids change within weeks of a medication change. |
| All four values and units | mg/dL or mmol/L. Convert before comparing. |
| LDL method | Calculated (which equation) or direct. A method change can explain a small step. |
| Fasting or not | Matters most for triglycerides. |
| Lab | Labs can differ in LDL method and in the ranges they print. |
| Medications | Starts, stops, and dose changes, with dates. Statins, ezetimibe, PCSK9 drugs, and fish oil, plus anything else that affects lipids. |
| Other context | A recent illness, pregnancy, thyroid changes, a big change in weight or diet. |
The tests also go by many names. LDL appears as LDL, LDL-C, LDL Cholesterol, LDL Calc, Direct LDL, and Low Density Lipoprotein. Total cholesterol is sometimes just “Cholesterol”. Pick one name per test and use it everywhere, or your history will split into short, separate lines.
Charting it
You do not need to chart all four numbers every time. A few choices make the chart honest:
- Chart LDL on its own, with your goal drawn on it. That is the line most decisions are made from.
- Put LDL and HDL on one chart, or LDL and non-HDL, to see whether they move together.
- Chart triglycerides separately. They are much noisier than the others, and on a shared chart they make the cholesterol lines look flat.
- Space points by date. Panels five years apart and panels five weeks apart should not look evenly spaced.
- Mark medication changes, and look at the first panel 4 to 12 weeks after each.
How to track your lab results over time has the general method for any test, and the lab results spreadsheet template is a reasonable place to start if you have only a few panels.
Tracking cholesterol in HealthViewer
HealthViewer is a lab results tracker that runs on your own computer. It imports lipid panels from lab report PDFs, MyChart downloads, and direct connections to your health system, and files LDL, LDL-C, LDL Direct, and Low Density Lipoprotein under one test. Results in mmol/L are converted so they share one chart with results in mg/dL. Calculated and direct LDL are filed under the same test, so if your lab changed methods, a journal note on that date keeps the switch visible on the chart.
In Trends, the Heart tag and the Lipid Panel filter pull your lipid tests together. The overlay view puts LDL and HDL on one chart, and medication markers show where a statin started or a dose changed. Set your LDL goal as a custom range in the Test Catalog, and the chart shades your target instead of the lab’s cutoff.
Everything stays in an encrypted file on your computer, with no account and no cloud service. Getting Started walks through the first import.
This post is general information, not medical advice. Talk to your clinician about your cholesterol goal and before changing any treatment.