Most discussions around cholesterol focus on hypercholesterolemia (high cholesterol) because it’s very common and can lead to serious complications, including stroke and heart attack.
It’s also possible for your cholesterol to be too low. When this happens, it’s called hypocholesterolemia.
Having low cholesterol is much less common than having high cholesterol, so we know less about its causes and complications. In this article, we’ll break down the current research around hypocholesterolemia.
Doctors measure cholesterol levels with a blood test that presents the results in mg/dL (milligrams per deciliter).
Since most people are concerned about high cholesterol, it’s common to see information about what levels are too high. You don’t often see a minimum amount of cholesterol listed.
Hypocholesterolemia is when both your total cholesterol and LDL cholesterol levels are in the bottom 5% of the general population. Your doctors can determine this after adjusting for factors like age or sex.
Some research has looked at the effects of LDL cholesterol levels below 25 mg/dL and 15 mg/dL, so these may also be useful ways to define hypocholesterolemia.
Your thyroid is a gland that produces hormones. Thyroid hormones help your body use energy and break down lipids, including cholesterol.
If you have hyperthyroidism, your thyroid is overactive. It will make more thyroid hormones than your body needs, which can lead to your cholesterol levels dropping very low. Sometimes your cholesterol may drop low enough to be classified as hypocholesterolemia.
Pernicious anemia
Anemia is a condition in which you don’t have enough healthy blood cells. Pernicious anemia is one specific type of anemia.
Some research suggests anemia can lead to lower concentrations of cholesterol in your blood.
But other research found that B12 deficiency associated with pernicious anemia leads to higher cholesterol levels.
More research is needed to better understand the link between pernicious anemia and hypocholesterolemia.
Sepsis
Sepsis occurs when your body produces an extreme response to an infection. It’s often due to a respiratory tract infection like pneumonia.
Sepsis can also lead to hypocholesterolemia. A 2019 study of patients with sepsis from hospital-acquired pneumonia observed reduced levels of HDL, LDL, and other lipoproteins.
Liver disease
The liver plays a key role in regulating your cholesterol levels. People with chronic liver diseases, like hepatitis, can often have low blood cholesterol. According to 2020 research, lower cholesterol levels are linked to more severe liver disease.
Malabsorption
Malabsorption is when your small intestine cannot absorb nutrients from your food, including lipids. This means your body does not get the cholesterol that it needs.
If you have family members with FHBL or ABL, you may be at increased risk for these conditions. Both FHBL and ABL can lead to hypocholesterolemia.
If you have high cholesterol, your doctor may prescribe medications such as statins or PCSK9 inhibitors. According to some research, PCSK9 inhibitors may drop your cholesterol levels too low in some cases, leading to hypocholesterolemia. More research is still needed, though.
If your doctor prescribes PCSK9 inhibitors, you should continue taking them and discuss with your doctor how to monitor your cholesterol levels going forward.
If your cholesterol is too high, you may not know it until you have a severe complication such as a heart attack.
Similarly, if your cholesterol is too low, there aren’t likely to be very many noticeable symptoms. The best way to know if you have hypocholesterolemia is to have a doctor order a blood test.
There has been some evidence that hypocholesterolemia can cause depression, suicidal ideation, and other effects on your mood or behavior. But experts have been unable to easily replicate these results in further studies or have found contrary evidence.
There is not enough evidence to link hypocholesterolemia to any specific complications. While more research is needed, there are some reported links between hypocholesterolemia and:
Doctors order a blood test called a lipid profile to determine your cholesterol levels.
Sometimes you may need to fast for up to 12 hours before a cholesterol test. Your doctor can provide you with detailed instructions on how to prepare for the test.
A medical professional will draw your blood and send it to a lab for analysis. The results will typically include four measurements:
If you have hypocholesterolemia, the treatment will likely not be as simple as switching to a higher cholesterol diet unless the cause is malnutrition.
More likely, the cause of your hypocholesterolemia will be related to:
genetics
metabolism
medications you’re taking
You might need to:
start taking a new medication
switch medications
adjust the dosage
Your doctor will create a treatment plan based on your specific situation.
The effects of cholesterol levels outside of typical ranges, whether too low or too high, may go unnoticed for a long time. Regularly monitoring your cholesterol levels can help identify when your levels may be too high or too low.
Regular checkups are important. During your appointment, you can ask your healthcare team to take a lipid profile it’s not already included. To support overall heart health, the American Heart Association recommends the following:
Hypocholesterolemia is an extremely low level of both LDL and total cholesterol.
Experts have found evidence that hypocholesterolemia can have negative effects, but much more research is needed. Even deciding on what level of cholesterol should define hypocholesterolemia is still being debated.
When your cholesterol falls outside of typical ranges, whether too low or too high, there will be few, if any, noticeable symptoms.
Having regular checkups, including getting a lipid profile, is the best way to monitor your cholesterol levels. If you’re concerned about hypocholesterolemia, talk with a doctor to learn more.
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