Understanding Cholesterol Problems: The Basics

Medically Reviewed by James Beckerman, MD, FACC on June 14, 2021

What Are Cholesterol Problems?

Everyone's body needs cholesterol, but too much can spell trouble for some people. A soft, fat-like substance, cholesterol helps with vital body functions such as building new cells and making hormones.

The body gets cholesterol in two ways: 80% of it is made by the liver, and the rest comes from the food you eat. Cholesterol is found in foods from animal products like meat, cheese, poultry, or fish.

Foods that don't contain animal products may contain another harmful substance called trans fats, which cause your body to make more cholesterol. Also, foods with saturated fats cause the body to make more cholesterol. Foods high in sugar are also associated with developing higher cholesterol levels in the blood.

Cholesterol is carried through the bloodstream by attaching to certain proteins. The combination is called a lipoprotein. There are four different types of lipoproteins that carry cholesterol in the blood:

  • High density lipoprotein (HDL) or "good cholesterol"
  • Low density lipoprotein (LDL) or "bad cholesterol"
  • Very low density lipoproteins (VLDL), which are very bad forms of cholesterol
  • Chylomicrons, which carry very little cholesterol but a lot of another fat called triglycerides

The amount of cholesterol in your bloodstream is important because of its role in various cardiovascular diseases. The risk of getting these conditions is complex and depends not only on how much cholesterol but also what kind of cholesterol you have in your blood. Generally speaking, high levels of LDL -- the "bad cholesterol" -- are associated with a higher chance of coronary heart disease; high levels of HDL -- or "good cholesterol" -- are associated with a lower chance.

LDL cholesterol collects in the walls of arteries, leading to "hardening of the arteries" or atherosclerosis. People with atherosclerosis are in turn vulnerable to heart failureheart attackstroke, and other problems caused by clogged blood vessels. Even so, some people who have high LDL cholesterol never get heart disease, and many heart attack patients do not have high cholesterol levels.

Cholesterol levels can increase with:

Since no one can predict which people with high cholesterol will develop heart disease, play it safe and keep your cholesterol levels in check. Dietary control alone does not work for everyone; some people will also need to take medication to reduce their cholesterol levels.

In general, the higher your HDL "good" cholesterol, the better. But some research has shown that if it's naturally very high -- over 100 mg/DL -- you might actually be at higher risk of heart disease. This could be because certain genetic factors can cause high HDL levels. We need more research into this.  

Another thing to keep in mind is triglycerides. Most of your body's fat is triglycerides. It's not clear whether high triglycerides alone increase your risk of heart disease, but many people with high triglycerides also have high LDL or low HDL levels, which do increase the risk of heart disease.

Having low cholesterol levels is not immediately harmful to the body, but it may mean you have another medical condition that needs treatment (like hyperthyroidism, malnutrition, pernicious anemia, or sepsis).

Who Develops Cholesterol Problems?

Most cholesterol problems are passed down in families. Some families have low total cholesterol or high levels of HDL ("good cholesterol"), regardless of diet or lifestyle. Other families inherit genes that increase their risk for high cholesterol. In these people, eating a diet high in saturated fat can significantly raise cholesterol levels. Stress can also raise blood cholesterol levels, especially since stress can lead to poor eating habits that may increase cholesterol intake.

On the positive side, vigorous exercisers -- such as long-distance runners -- tend to have high HDL cholesterol levels. Before menopause, women tend to have higher HDL cholesterol than men their age.