Cholesterol is a substance that the body needs to function. High or low cholesterol levels can cause adverse effects and are a health risk.

Many people recognize that there are health risks of high cholesterol, but there is less information and research about the effects of lower levels. Low cholesterol may occur with genetic conditions or due to other factors.

This article discusses cholesterol in more detail, including the dangers of low cholesterol, its causes, diagnosis, and treatment.

A note about sex and gender

Sex and gender exist on spectrums. This article will use the terms “male,” “female,” or both to refer to sex assigned at birth. Click here to learn more.

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Cholesterol is a waxy, fat-like substance that the body needs for good health. The liver makes cholesterol, and it is present in certain foods.

The substance has a range of essential functions in the body, including the synthesis of bile acids, hormones, and vitamin D. The principal function of cholesterol is to maintain the fluidity and integrity of cell membranes.

However, high cholesterol is a risk factor for cardiovascular disease, so it is important for people to try to keep their cholesterol levels within healthy parameters.

Doctors look at several factors when assessing a person’s cholesterol profile. These include:

  • total cholesterol, which is the total amount of cholesterol in the blood
  • low-density lipoprotein (LDL), which people refer to as “bad” cholesterol
  • high-density lipoprotein (HDL), which people refer to as “good” cholesterol
  • triglycerides, which is a type of fat in the blood that the body uses for energy

Learn more about the differences between HDL and LDL here.

While high cholesterol is relatively common in the United States, low cholesterol is less frequent.

“Hypocholesterolemia” is the medical term for low cholesterol. A person may have hypocholesterolemia due to inheritable conditions, but it can have other causes.

Some genetic conditions that may cause low cholesterol are:

  • hypobetalipoproteinemia
  • abetalipoproteinemia
  • chylomicron retention disease

These rare conditions arise because of familial mutations in genes involved in how the body processes fats. They may cause severe symptoms if doctors do not diagnose them early in life.

“Hypolipidemia” is another term for low cholesterol levels. In addition to genetic factors, there may be more common causes of hypolipidemia, including:

Another cause of low cholesterol may be cholesterol-lowering medication. Additionally, a person’s HDL cholesterol levels may be too low. Doctors tend to look at a person’s complete lipid and cholesterol profiles when assessing their risk.

Experts advise that the following factors may cause low HDL:

Rare genetic conditions, such as abetalipoproteinemia, that cause low cholesterol may have the following effects on the body:

Getting a diagnosis and treatment from a doctor as early as possible may prevent death.

Additionally, an animal study suggested that low cholesterol may decrease serotonin and cause aggression. A study with human participants indicated there may be a link between low cholesterol with aggression and suicide attempts. However, both studies have limitations and further research is necessary.

One study suggested that low cholesterol may increase a person’s risk of death. Another study showed there is an association between low cholesterol, liver dysfunction, and dying from cancer.

Finally, a research review recommended that healthcare professionals monitor patients taking cholesterol-lowering drugs called PCSK9 inhibitors.

A doctor can diagnose low cholesterol using a blood test.

According to the Centers for Disease Control and Prevention (CDC), desirable lipid profile levels are as follows:

  • Total cholesterol: around 150 milligrams per deciliter (mg/dL)
  • LDL cholesterol: around 100 mg/dL
  • HDL cholesterol: at least 50 mg/dL in females and 40 mg/dL in males
  • Triglycerides: less than 150 mg/dL

If a person’s HDL is too low, or their total cholesterol or LDL is lower than average, a doctor may diagnose low cholesterol.

Doctors may notice signs of rare genetic diseases that cause low cholesterol early in a person’s life. As a result, they may recommend genetic testing to help diagnose a condition.

Experts advise that doctors may treat genetic conditions causing low cholesterol with dietary changes and supplements. The treatment may include high dose vitamin E, dietary fat, and other fat-soluble vitamins.

If someone’s cholesterol reaches low levels due to their medication, a doctor may assess their dosage or recommend an alternative medication.

Rare genetic conditions can alter how someone metabolizes fats and lower their cholesterol to unhealthy levels. This may cause adverse effects and even death.

Research also indicates that medications that lower cholesterol may cause side effects and risks to a person’s overall health if levels become extremely low. Low cholesterol may affect various parts of a person’s body, including the nervous system and eyes.

A person may want to consider asking their doctor for a blood test if they wish to know their cholesterol levels or if they have symptoms of low cholesterol.