Heart markers
High Triglycerides UK: What Your Number Actually Means
Reviewed by a qualified clinician · analysed at UKAS-accredited UK labs (ISO 15189)
Last reviewed September 20265 min read
Every Helvy guide is written by our health editors, then checked by a qualified clinician before it goes live and re-checked as the science moves. We name clinical roles, not individuals, until each reviewer has agreed to be credited publicly. This is wellness guidance to help you understand your own data, not a diagnosis.
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HEART UK says aim below 1.7 mmol/L if you fasted, and below 2.0 if you did not. Triglycerides are the fat your body stores energy in. NICE does not change its advice until 4.5, so most flagged results sit in a wide band where diet, alcohol and weight matter more than the exact figure.
Not sure which markers you need? Build your test →Your triglycerides came back at 2.4 and the report has flagged them. Your cholesterol looked fine. You are trying to work out whether this is a small thing or a big one.
It is usually a small thing, and the reason is that the flag fires early. A 2.4 and a 12 both get marked high on the same report, and they are not remotely the same situation.
1. What counts as high triglycerides in the UK?
Triglycerides are fat carried in your blood. You get them from food, and your body also makes them from calories it is not using yet. After a meal the level climbs, then falls again.
The cholesterol charity HEART UK gives two targets, because the answer depends on whether you ate.
| Source | Figure |
|---|---|
| HEART UK, fasting | Below 1.7 mmol/L |
| HEART UK, non-fasting | Below 2.0 mmol/L |
| Gloucestershire Hospitals, fasting | 0.6 to 1.9 mmol/L |
Notice the gap. A fasting 1.8 is above HEART UK's target and inside Gloucestershire's reference range. Both are right. One is a health target, the other describes what most people's results look like.
2. What are the bands NICE actually acts on?
This is the useful part. NICE sets out what a clinician does at each level, and the first threshold is a long way above the flag.
| Level | What NICE advises |
|---|---|
| Under 4.5 mmol/L | No specific triglyceride action is set out |
| 4.5 to 9.9 mmol/L | Risk tools may underestimate you, so other risk factors get attention |
| 10 to 20 mmol/L | Repeat as a fasting test, and look for a secondary cause |
| Over 20 mmol/L | Urgent specialist review |
The middle band is worded carefully, and it is worth reading as written:
“In people with a triglyceride level between 4.5 mmol and 9.9 mmol per litre: be aware that the CVD risk may be underestimated by risk assessment tools.”
NICE guideline NG238, recommendation 1.4.8
CVD means cardiovascular disease. The point is subtle and it matters. The standard UK risk calculator does not use triglycerides, so a high figure can make that score look better than your picture really is. That is why the other markers get looked at harder.
3. What pushes triglycerides up?
NICE calls these secondary causes, meaning something else is driving the number rather than the fat itself being the problem. Its recommendation names five:
- Alcohol. Heavy intake is one of the strongest single drivers.
- Diabetes that is not well controlled. Blood sugar and triglycerides move together.
- An underactive thyroid. Slower metabolism lifts lipids.
- Liver disease.
- Nephrotic syndrome, a kidney condition that leaks protein into urine.
NICE puts it as a sequence. Exclude the common secondary causes, including excess alcohol intake, uncontrolled diabetes, hypothyroidism, liver disease and nephrotic syndrome, before referring anyone for specialist review.
Two of those are things a blood test can look at directly. If your triglycerides are up, a TSH test for the thyroid and an HbA1c for blood sugar are sensible company. Liver disease is the third on that NICE list, and the fatty liver blood test normal range shows how little a normal ALT settles. Our guide on thyroid and cholesterol covers that link, and the cholesterol blood test guide walks the full lipid panel.
Weight, refined carbohydrate and how much you move all shift the number too. Triglycerides respond to changes faster than LDL does, which is part of why they are worth retesting. Our guide on lowering triglycerides has the evidence behind that.
4. Why does fasting change the number?
Because triglycerides rise after you eat, and they rise more than any other lipid. A result taken two hours after lunch is a different measurement from one taken before breakfast.
That is why NICE asks for a fasting repeat once the figure passes 10, after a gap of five days but within two weeks. And it is why HEART UK publishes separate fasting and non-fasting targets rather than one number.
Gloucestershire asks for a 12 to 14 hour fast for a full lipid profile. If yours was a non-fasting sample and the figure is only mildly up, that alone can explain it. Our guide on fasting before a blood test has the practical detail, and alcohol before a blood test covers the other big one.
5. Which blood test includes triglycerides?
Any standard lipid profile, so an NHS cholesterol check will have given you one. Helvy measures triglycerides in three panels.
- Advanced Heart Health reads them with ApoB, Lp(a), hs-CRP and HbA1c.
- General Energy & Wellness reads them with your cholesterol, thyroid, cortisol and vitamin markers.
- Thyroid & Vital Organs reads them alongside your thyroid, kidney and liver numbers.
All three are home finger-prick kits processed by UKAS-accredited UK labs. If the thyroid link above is what you want checked, the two panels carrying TSH are the ones to look at. If you are unsure, the build-my-test tool walks you through it in about a minute.
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See your triglycerides next to the numbers that explain them
Helvy's home blood tests report triglycerides with plain-English context, so a figure just over a target never sparks a needless panic. Samples are processed by UKAS-accredited UK labs.
Frequently asked questions
What is a high triglyceride level in the UK?
HEART UK sets the fasting target below 1.7 mmol/L and the non-fasting target below 2.0. NICE describes 4.5 to 9.9 as the band where cardiovascular risk tools may underestimate you.
Are triglycerides of 2.4 dangerous?
A 2.4 sits above HEART UK's target and well below every NICE threshold. It is worth acting on through diet, alcohol and weight, and worth retesting. It is not an emergency figure.
What triglyceride level needs a specialist?
NICE advises urgent specialist review above 20 mmol/L where that is not explained by alcohol or poor blood sugar control, and specialist advice if a level stays above 10 on a fasting repeat.
Can an underactive thyroid raise triglycerides?
NICE lists hypothyroidism among the common secondary causes to exclude before referring anyone for specialist review. A TSH test is a reasonable thing to run alongside a lipid panel.
Do I need to fast for a triglyceride test?
Not for an initial check, but it changes the number. Triglycerides rise after eating more than other lipids do, which is why HEART UK publishes separate fasting and non-fasting targets.
How quickly can triglycerides come down?
Faster than LDL cholesterol does, which is why they are worth retesting after a change. Speak to a qualified clinician about what to change and when to measure again.
Why is my cholesterol fine but triglycerides high?
They are measured together but they track different things. Triglycerides respond quickly to recent meals, alcohol and weight, while LDL moves more slowly.
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