🩺

Medically reviewed by the Vital Signs Today Medical Review Board. Last updated 18 June 2026. Every range and figure below is drawn from the peer-reviewed and clinical sources listed at the end of this article.
Key takeaways

  • Low triglycerides usually means a value under about 40 mg/dL, since a normal fasting triglyceride level is below 150 mg/dL (Cleveland Clinic).
  • Mildly low triglycerides are often harmless and reflect a lean body, a low-fat or low-carb diet, or regular exercise, and they are not a recognized heart risk on their own.
  • Very low triglycerides can sometimes flag an underlying problem such as an overactive thyroid, malnutrition, fat malabsorption, or a rare inherited condition, so the result should be read alongside your other labs and symptoms.

Most people open a lipid panel braced for a number that is too high. So a low triglyceride reading can feel confusing. In the large majority of cases it is reassuring, but in a minority it is a quiet clue that your body is not absorbing or storing fat the way it should. Here is how to tell which situation you are in.

Part of our Lipid Panel guide.

What does a low triglyceride result mean, and what is the cutoff?

A low triglyceride result generally means your fasting value falls under roughly 40 mg/dL, because a normal level is defined as below 150 mg/dL (Cleveland Clinic). Triglycerides are the most common type of fat in your blood, and they store unused calories so your body can call on them for energy later. There is no formal “too low” diagnostic threshold the way there is for high triglycerides, which is part of why low values get little attention.

Here is the practical scale clinicians use:

  • Normal: below 150 mg/dL.
  • Considered low / optimal: below 100 mg/dL, which the Cleveland Clinic calls ideal.
  • Notably low: under about 40 mg/dL, the point where a doctor may look for a cause.

A single low number is rarely alarming. The pattern across your whole lipid panel matters far more than one isolated value.

Want to check triglycerides yourself?

Check your triglycerides and 100+ other biomarkers from home with one Superpower panel, reviewed by a physician.

See what Superpower tests →

What causes low triglycerides?

Low triglycerides are most often caused by lifestyle and body composition, and less often by a medical condition. A common driver is simply eating a low-fat or very low-carbohydrate diet, since dietary fat and excess carbohydrate are the raw material your liver turns into triglycerides. Being lean and physically active lowers them too, because exercise burns circulating fat for fuel.

When the cause is medical, the usual suspects are:

  • Hyperthyroidism: an overactive thyroid speeds up metabolism and burns through fats quickly, pulling triglycerides down (SiPhox Health).
  • Malnutrition or undereating: when calories are scarce, the body depletes its fat stores for energy.
  • Malabsorption: conditions such as celiac disease, Crohn disease, or chronic pancreatitis stop the gut from absorbing dietary fat properly.
  • Inherited low lipids: rare genetic conditions such as familial hypobetalipoproteinemia, caused by APOB gene changes, keep both cholesterol and triglycerides low for life (HEART UK).
  • Medications: some lipid-lowering and other drugs can push triglycerides down as a side effect.

Are there symptoms, or is it silent?

Low triglycerides themselves produce no symptoms and are silent, which is why they are almost always found by accident on a routine lipid panel rather than because someone felt unwell. The triglyceride number is not something you can feel.

What you may notice are signs of the underlying condition, if one exists. An overactive thyroid can bring unexplained weight loss, a racing heart, tremor, heat intolerance, and anxiety. Fat malabsorption from celiac or Crohn disease can cause diarrhea, pale or greasy stools, bloating, and fatigue. Because fat carries the fat-soluble vitamins A, D, E, and K, long-standing severe malabsorption or inherited low-lipid conditions can eventually lead to vitamin deficiencies that affect vision, bones, and nerves (HEART UK). If your triglycerides are very low and you have any of these symptoms, that combination is the real signal, not the lipid value alone.

When are low triglycerides actually dangerous?

Low triglycerides are not dangerous in themselves, and there is no established heart or stroke risk from having them low. The danger, when it exists, comes entirely from the cause behind a very low value, typically under about 40 mg/dL.

Concern rises when a low triglyceride level appears together with other red flags: unexplained weight loss, chronic diarrhea or greasy stools, low cholesterol across the board, or symptoms of an overactive thyroid. In that setting the number may be pointing at hyperthyroidism, malnutrition, or a malabsorption disorder that does need treatment (SiPhox Health). The inherited forms, although rare, matter because the long-term shortfall of fat-soluble vitamins can damage nerves and vision if it goes unaddressed. So the rule is simple: low and otherwise well is fine, while low plus symptoms deserves a closer look.

What should you do next, and when should you see a doctor?

If your triglycerides are mildly low and you feel well, the next step is usually nothing more than noting it and rechecking at your next routine panel, because for most people a low value is benign or even favorable. Make sure the test was done fasting, since eating beforehand and day-to-day variation can both move the number (Cleveland Clinic).

See a doctor sooner if any of the following apply:

  • Your triglycerides are very low, under about 40 mg/dL, especially if your total and LDL cholesterol are also unusually low.
  • You have unexplained weight loss, ongoing diarrhea, pale or greasy stools, or persistent fatigue.
  • You have symptoms of an overactive thyroid such as palpitations, tremor, or heat intolerance.
  • You eat very little or have a known gut condition such as celiac or Crohn disease.

Your clinician can order thyroid tests, check for malabsorption, and review the rest of your lipid panel to decide whether the low value means anything.

The insider nuance most reports skip

Here is the part that rarely makes it into a lab printout: low triglycerides are interpreted in context, not in isolation, because the same number can be a sign of excellent metabolic health in one person and a warning in another. A fit athlete on a clean diet and a person with untreated celiac disease can show the same low triglyceride value for completely opposite reasons.

What separates the two is the company the number keeps. Low triglycerides with normal cholesterol, normal weight, and no symptoms is the picture of good metabolic health, and many clinicians view triglycerides under 100 mg/dL as ideal. Low triglycerides alongside low cholesterol, weight loss, or gut symptoms is the version that warrants investigation. This is why a good clinician never reacts to the triglyceride line alone. They read it next to your cholesterol, your thyroid, your weight history, and how you actually feel.

Related reading

Frequently asked questions

Is a low triglyceride level good or bad?

For most people it is good or neutral. Mildly low triglycerides often reflect a lean body, a healthy diet, or regular exercise, and carry no known heart risk. It only becomes a concern when the value is very low and paired with symptoms or other abnormal labs.

What is considered a low triglyceride level?

Since normal is below 150 mg/dL, levels under about 40 mg/dL are usually considered low, and many clinicians treat below 100 mg/dL as ideal (Cleveland Clinic). There is no strict diagnostic cutoff for “too low” the way there is for high values.

Can low triglycerides mean a thyroid problem?

Yes. An overactive thyroid, or hyperthyroidism, speeds up metabolism and burns fat quickly, which can lower triglycerides. If your level is low along with weight loss, a racing heart, or tremor, your doctor may order thyroid tests.

Do I need to fast before a triglyceride test?

Fasting gives the most accurate triglyceride result, because eating raises the number temporarily. Many panels ask for an 8 to 12 hour fast. A low value on a fasting test is more meaningful than one taken after a meal.

Can low triglycerides cause vitamin deficiency?

Not directly. But the conditions behind very low triglycerides, such as fat malabsorption or rare inherited low-lipid disorders, can reduce absorption of fat-soluble vitamins A, D, E, and K over time (HEART UK), which is one reason a persistently very low value gets investigated.

Sources

This article is for general educational purposes and is not medical advice. It cannot diagnose or treat you and does not replace your clinician. Always discuss your lab results and any health decisions with a qualified healthcare professional.