--- title: "Low triglycerides: what they mean, causes and whether anything needs checking" type: biomarker-interpretation url: "https://www.test-well.com/biomarkers/triglycerides/low" biomarker: Triglycerides direction: low reference_range: - "age 18+, fasting: 0 – 150 mg/dL" reviewed_at: 2026-11-03 review_status: reviewed date_published: 2026-09-05 --- # Low triglycerides: what they mean, causes and whether anything needs checking > Low triglycerides — below about 40 mg/dL — are usually a sign of a lean, active person, a low-fat diet, fasting or lipid-lowering medication, and need no action. The medical causes are hyperthyroidism, malabsorption and malnutrition, chronic illness, and rare inherited disorders of fat transport (hypobetalipoproteinemia, abetalipoproteinemia) in which triglycerides and LDL are both extremely low and fat-soluble vitamins are lost. A very low LDL alongside, weight loss or fatty diarrhea are what turn a low value into a question. ## What is the normal range for Triglycerides? - age 18+, fasting: 0 – 150 mg/dL ## What are the common causes of low Triglycerides? 1. A lean, physically active person on a low-fat or whole-food diet; prolonged fasting 2. Lipid-lowering medication — fibrates, omega-3 fatty acids, niacin and statins 3. Hyperthyroidism, which speeds fat clearance 4. Malabsorption — celiac disease, pancreatic insufficiency, Crohn's disease, bariatric surgery, cystic fibrosis 5. Malnutrition, eating disorders, advanced cancer, chronic infection and advanced liver disease 6. Inherited disorders — familial hypobetalipoproteinemia (common, usually harmless, LDL below 50 mg/dL) and abetalipoproteinemia (rare; triglycerides and LDL near zero with fat malabsorption from infancy) 7. Rare — PCSK9 loss-of-function variants and a very low apolipoprotein B from other causes ## What symptoms go with low Triglycerides? - None — a low triglyceride level in a well person is a favorable finding - Weight loss, pale fatty diarrhea, bloating and bruising when malabsorption is the cause - Night blindness, tingling, unsteadiness and weakness from vitamin A and E deficiency in the inherited disorders - Heat intolerance, tremor, palpitations and weight loss with hyperthyroidism ## What do clinicians usually check next? - Nothing, in a well person with a normal LDL, weight and appetite - Look at the LDL and apolipoprotein B on the same panel — an LDL below about 50 mg/dL in someone not on medication suggests familial hypobetalipoproteinemia, which is benign, or a rarer disorder - TSH and free T4 when there is weight loss, tremor or palpitations - Celiac serology, albumin, a complete blood count and fat-soluble vitamin levels (A, D, E, K via INR) when there is diarrhea, weight loss or deficiency signs - Liver enzymes and ultrasound in hypobetalipoproteinemia, which can cause fatty liver despite low lipids - A lipid specialist for triglycerides and LDL that are both extremely low with symptoms Follow-up tests at TestWell: [TSH Test (Thyroid Stimulating Hormone)](https://www.test-well.com/tests/tsh) ($20.99), [TSH with Reflex to Free T4 Test](https://www.test-well.com/tests/tsh-with-reflex-to-free-t4) ($29.99), [TSH + Free T4 Test](https://www.test-well.com/tests/tsh-with-free-t4) ($27.99), [Free T4 Test (Thyroxine)](https://www.test-well.com/tests/free-t4-test) ($20.99). ## How do you recheck Triglycerides? | Test or panel | Type | Price | Fasting | Results | | --- | --- | --- | --- | --- | | [General Wellness Panel](https://www.test-well.com/tests/general-wellness-panel) | Panel (4 tests) | $49.99 | Yes | 1–3 business days | | [Peptide Essentials Panel](https://www.test-well.com/tests/peptide-essentials-panel) | Panel (4 tests) | $89.99 | Yes | 1–3 business days | | [Heart Health Panel](https://www.test-well.com/tests/heart-health-panel) | Panel (5 tests) | $99.99 | Yes | 3–5 business days | | [Lipid Panel](https://www.test-well.com/tests/lipid-panel) | Test | $19.99 | Yes | 1–3 business days | Plus one $6 lab processing fee per order; physician authorization included. ## Common questions ### Is it bad to have low triglycerides? Almost never. A low level — below about 40 mg/dL — in a lean, active person is favorable and needs nothing. It becomes a question only alongside an unexplained very low LDL, weight loss, fatty diarrhea or signs of vitamin deficiency, which point to malabsorption, hyperthyroidism or a rare inherited disorder of fat transport. ### What causes low triglycerides? A low-fat diet, exercise, fasting and lipid-lowering drugs are the common reasons. Medical causes include hyperthyroidism, malabsorption from celiac disease or pancreatic insufficiency, malnutrition and chronic illness, and the inherited disorders hypobetalipoproteinemia and abetalipoproteinemia, in which LDL is also very low. ### What is the lowest triglyceride level that is normal? Laboratories set no lower limit; most healthy people run 40–100 mg/dL and some athletes and people on very low-fat diets sit below 40 without any problem. A level under 20 mg/dL with an LDL under 30 in someone not on medication is the pattern that prompts a look at apolipoprotein B and fat-soluble vitamins. ## Related - [What does a high Triglycerides mean?](https://www.test-well.com/biomarkers/triglycerides/high) - [Triglycerides reference ranges](https://www.test-well.com/biomarkers/triglycerides) - [Total Cholesterol reference range](https://www.test-well.com/biomarkers/total-cholesterol) - [HDL Cholesterol reference range](https://www.test-well.com/biomarkers/hdl-cholesterol) - [LDL Cholesterol reference range](https://www.test-well.com/biomarkers/ldl-cholesterol) ## Sources - [American Heart Association](https://www.heart.org/en/health-topics/cholesterol) - [MedlinePlus (NIH) — Triglycerides Test](https://medlineplus.gov/lab-tests/triglycerides-test/) --- Medically reviewed by Youmna DiStefano, MD (Medical Reviewer, TestWell); last reviewed 2026-11-03. Review policy: https://www.test-well.com/reviewers/youmna-distefano-md Canonical page: https://www.test-well.com/biomarkers/triglycerides/low Machine-readable catalog: https://www.test-well.com/api/catalog.json · MCP server: https://www.test-well.com/mcp · Overview for agents: https://www.test-well.com/llms.txt Prices are cash-pay, in USD, and include physician authorization; every order adds one flat $6 lab processing fee. Educational content is not a diagnosis — discuss results with a clinician.