Your body needs cholesterol to make hormones, vitamin D, and digestive fluids. However, too much of one type of cholesterol can contribute to cardiovascular disease and your risk of stroke.

Cholesterol is a waxy substance found in your blood and in your cells. Your liver makes most of the cholesterol in your body. The rest comes from foods you eat. Cholesterol travels in your blood bundled up in packets called lipoproteins.

  • Low-density lipoprotein (LDL): This is the “bad,” unhealthy kind of cholesterol. LDL cholesterol can build up on the sides of your blood vessels. That buildup is called plaque. Plaque buildup from LDL cholesterol can thicken the walls of your blood vessels and narrow the channels within your arteries, reducing blood flow.
  • High-density lipoprotein (HDL): This is the “good,” healthy kind of cholesterol. It transports excess cholesterol out of your arteries to your liver, which removes it from your body.

Cholesterol itself isn’t bad. Your body needs some cholesterol to make hormones, vitamin D, and digestive fluids. Cholesterol also helps your organs function properly.

Yet too much of one type of cholesterol can contribute to cardiovascular disease and increase your risk for stroke.

This article explores the effects — both symptoms and complications — of high cholesterol in your body.

Terms to know

Blood vessel vs. artery: Blood vessel is an umbrella term for arteries and veins. Arteries and veins are pipelines of muscle through which your blood flows. Arteries carry blood from your heart to the rest of your body, while veins push blood from your body back to your heart.

Coronary vs. heart: These two terms mean the same thing and can be used interchangeably, as in “heart disease” or “coronary disease.”

When you have too much LDL cholesterol in your body, it can build up in your arteries, making them less flexible and potentially clogging them. Hardening of the arteries is called atherosclerosis. Blood doesn’t flow as well through stiff arteries, so your heart has to work harder to push blood through them.

The buildup of plaque in the arteries can affect all organs, but more specifically, it can affect the heart, brain, and blood supply to the stomach, legs, or feet.

When plaque builds up in coronary arteries, it can disrupt the flow of oxygen-rich blood to your heart muscle. This may cause chest pain called angina. Angina indicates a temporary disruption of blood flow and can signal that you’re at risk for a heart attack.

A heart attack typically occurs when a piece of plaque breaks off and forms a clot that blocks the entire artery. This disrupts blood flow to part of the heart, which can lead to a heart attack.

If this process occurs in the brain, it is called a stroke. There are different types of stroke, and this is one of the causes.

Plaque can also block the flow of blood to arteries that supply blood to your intestinal tract, legs, and feet. This is called peripheral arterial disease (PAD).

Your body’s hormone-producing glands use cholesterol to make hormones such as estrogen, testosterone, and cortisol. Hormones can also have an effect on your body’s cholesterol levels.

Research has shown that as estrogen levels rise during a woman’s menstrual cycle, HDL cholesterol levels also go up, and LDL cholesterol levels decline. This may be one reason why a woman’s risk for heart disease increases after menopause, when estrogen levels drop.

Lowered production of thyroid hormone (hypothyroidism) leads to an increase in total and LDL cholesterol. Excess thyroid hormone (hyperthyroidism) has the opposite effect.

Androgen deprivation therapy, which reduces levels of male hormones to stop prostate cancer growth, can raise LDL cholesterol levels. A deficiency of growth hormone can also raise LDL cholesterol levels.

Cholesterol is an essential component of the human brain. In fact, the brain contains about 20% of the body’s entire supply of cholesterol. This fat is essential for the development and protection of nerve cells, which enable the brain to communicate with the rest of the body.

While you need some cholesterol for your brain to function optimally, too much of it can be damaging. Excess cholesterol in the arteries can lead to stroke — a disruption in blood flow that can damage parts of the brain. A stroke can negatively affect a number of cognitive functions, causing:

  • loss of memory
  • impaired movement
  • difficulty swallowing
  • difficulty with speech

High blood cholesterol on its own has also been implicated in the loss of memory and mental function.

High LDL cholesterol has also been associated with the risk of vascular dementia, a type of dementia that affects memory, thinking, and behavior.

In the digestive system, cholesterol is essential for the production of bile, a substance that helps your body break down foods and absorb nutrients in your intestines. But if you have too much cholesterol in your bile, the excess may form into crystals and then hard stones in your gallbladder, called gallstones.

Keeping an eye on your cholesterol level with recommended blood tests and lowering your risk for heart disease will help improve your overall quality of life.

Cholesterol by itself isn’t bad. In fact, your body needs cholesterol to make hormones, vitamin D, and digestive fluids, and to help your organs function properly.

Yet having too much LDL cholesterol can, over time, damage your arteries, contribute to heart disease, and increase your risk for stroke.

Getting your cholesterol checked at regular doctor visits and lowering your risk of heart disease with diet, exercise, lifestyle changes, and medication can decrease potential heart complications and improve your quality of life.