🩺

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 cholesterol on a blood test usually means a total cholesterol under about 116 to 120 mg/dL or an LDL under roughly 40 to 50 mg/dL, a state doctors call hypocholesterolemia (Cleveland Clinic; StatPearls).
  • Most low cholesterol comes from a treatable secondary cause such as statin therapy, an overactive thyroid, liver disease, or malnutrition rather than from a rare inherited disorder (Merck Manual; StatPearls).
  • A low cholesterol number is often harmless and causes no symptoms, but very low or unexplained results should be checked by a clinician to rule out an underlying illness (Mayo Clinic; Cleveland Clinic).

Most people worry when cholesterol is high, so seeing a low number can be confusing. In many cases low cholesterol is nothing to fear, and for people on cholesterol medication it is the goal. But because cholesterol is a building block your body needs, an unexpectedly low result is worth understanding. Here is what the number means, what drives it down, and when it deserves a closer look.

Part of our Lipid Panel guide.

What does low cholesterol mean and what is the cutoff?

Low cholesterol, medically called hypocholesterolemia, generally means a total cholesterol below about 116 mg/dL, putting you lower than more than 9 out of 10 people (Cleveland Clinic). There is no single universal cutoff. Many clinicians and researchers define hypolipidemia as a total cholesterol under 120 mg/dL or an LDL (“bad” cholesterol) under 50 mg/dL, with LDL considered very low under 40 mg/dL (StatPearls).

It helps to know which number is low, because they mean different things:

  • Total cholesterol: the sum of all cholesterol in your blood. A reading under about 120 mg/dL is generally called low.
  • LDL cholesterol: the type that drives plaque buildup. Lower is usually better for the heart, which is why statins push it down on purpose.
  • HDL cholesterol: the protective type. Here, low is a concern. An HDL under 40 mg/dL in men or under 50 mg/dL in women is a recognized cardiovascular risk factor (American Heart Association).

So a low LDL with normal HDL is often a healthy or treatment-driven picture, while a low HDL is the version of “low cholesterol” you actually want to raise.

Want to check cholesterol yourself?

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

See what Superpower tests →

What causes low cholesterol?

Most low cholesterol comes from a secondary cause, meaning another condition or medication is lowering it, and these are far more common than inherited causes (Merck Manual). The single most frequent reason in adults is intended treatment with statins or other lipid-lowering drugs (StatPearls).

Common drivers include:

  • Statins and other lipid-lowering medicines: these are designed to lower LDL and are the leading reason for a low result.
  • Overactive thyroid (hyperthyroidism): speeds metabolism and can pull cholesterol down (Cleveland Clinic).
  • Liver disease: the liver makes most of your cholesterol, so significant liver damage lowers production.
  • Malnutrition or malabsorption: conditions such as celiac disease, or simply not eating enough, reduce the raw materials.
  • Serious acute illness: infection, inflammation, and some cancers such as leukemia can temporarily lower levels.
  • Rare genetic conditions: abetalipoproteinemia and hypobetalipoproteinemia run in families and can cause very low lifelong levels (Cleveland Clinic).

What are the symptoms, or is it silent?

Low cholesterol itself is usually silent and produces no symptoms at all, which is why it is almost always discovered on a routine blood test rather than because a person feels unwell (Cleveland Clinic). When symptoms do appear, they typically come from the underlying cause, not from the low cholesterol number itself.

For example, an overactive thyroid may bring weight loss, a racing heart, and anxiety; malabsorption may cause diarrhea and weight loss; and rare inherited forms can cause fatty, foul-smelling stools, poor muscle control, and problems with growth in children (Cleveland Clinic; MedlinePlus). If you have a low result alongside any of these patterns, the symptoms are the clue worth chasing, not the cholesterol value on its own.

When is low cholesterol dangerous?

For most people, very low cholesterol does not cause harm, and it is often unclear whether low cholesterol causes a health problem or simply reflects one that is already present (Mayo Clinic). The danger usually lies in the underlying condition, such as liver disease or an undiagnosed illness, rather than in the number.

Some research has linked very low cholesterol to higher rates of certain conditions, including a possible association with hemorrhagic (bleeding) stroke and with depression and anxiety, but these links are associations and do not prove that low cholesterol is the cause (Mayo Clinic; Healthline). A separate and clearer concern is low HDL: an HDL under 40 mg/dL in men or 50 mg/dL in women predicts higher cardiovascular risk even when LDL is well controlled (American Heart Association). Pregnancy is one situation where unexplained very low cholesterol deserves prompt attention because of possible effects on the developing baby.

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

The first step is simple: talk to the clinician who ordered the test, because a single low value rarely tells the whole story and may just need rechecking (Cleveland Clinic). If you take a statin, a low LDL is usually expected and a sign the medicine is working, so do not stop it on your own.

See a doctor sooner rather than later if your low cholesterol is new and unexplained, if it is very low (for instance total cholesterol well under 100 mg/dL), or if it comes with weight loss, diarrhea, fatigue, or other symptoms. Your clinician may repeat the lipid panel after fasting, check thyroid and liver function, review your medications and diet, and screen for malabsorption. In the rare case of a suspected inherited disorder, especially in a child with poor growth, referral to a specialist is appropriate.

Insider nuance: low LDL is usually good news, low HDL is the real warning

The most useful thing to understand is that “low cholesterol” is not one finding. A low LDL with a healthy HDL is generally a favorable, heart-protective result and is exactly what cholesterol treatment aims for (StatPearls). What clinicians actually watch with concern is a low HDL, because protective HDL helps clear cholesterol from arteries, and an HDL of 60 mg/dL or above is considered protective against heart disease (American Heart Association).

So before assuming a low cholesterol result is a problem, look at which number is low. A patient proud of a total cholesterol of 150 mg/dL might actually have a worrying HDL of 35 mg/dL hidden inside that total. Reading the full lipid panel, not just the headline number, is what separates reassuring results from ones that need action.

Related reading

Frequently asked questions

Is low cholesterol good or bad?

It depends on which cholesterol is low. A low LDL is usually good and is the goal of statin therapy. A low HDL is unfavorable because HDL is protective. Very low total cholesterol without a clear reason should be checked by a doctor (Cleveland Clinic).

What number counts as low cholesterol?

Total cholesterol under about 116 to 120 mg/dL is generally considered low, and LDL under 40 to 50 mg/dL is low as well (Cleveland Clinic; StatPearls). There is no single universal cutoff, so your clinician interprets it alongside your health.

Can low cholesterol make you tired?

Low cholesterol itself rarely causes fatigue. Tiredness usually points to the underlying cause, such as an overactive thyroid, malnutrition, or liver disease, rather than to the low number on the test (Cleveland Clinic). Persistent fatigue with low cholesterol deserves evaluation.

Should I worry if my cholesterol is low on a statin?

Usually not. A low LDL on a statin is expected and means the medication is working as intended (StatPearls). Do not stop your statin on your own. If you feel unwell or the level seems very low, discuss it with your prescriber.

Can diet raise low cholesterol back to normal?

If low cholesterol comes from undereating or malabsorption, addressing nutrition can help. But when a treatable cause such as thyroid or liver disease is driving it, the priority is treating that condition (Merck Manual). Always confirm the cause with your clinician first.

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.