Cholesterol is a waxy, fat-like substance that your liver produces naturally. It’s vital for the formation of cell membranes, vitamin D, and certain hormones. Cholesterol doesn’t dissolve in water and therefore can't travel through the body itself. Particles known as lipoproteins help transport cholesterol through the bloodstream. There are two major forms of lipoproteins.
Low-density lipoproteins (LDL), also known as "bad cholesterol," can build up in the arteries and lead to serious health problems, such as a heart attack or stroke. High-density lipoproteins (HDL), sometimes called "good cholesterol," help return the LDL cholesterol to the liver for elimination.
Eating too many foods that contain excessive amounts fat increase the level of LDL cholesterol in your blood. This is a condition called high cholesterol, also known as hypercholesterolemia. If levels of LDL cholesterol are too high or levels of HDL cholesterol are too low, fatty deposits build up in your blood vessels. Eventually, these deposits make it difficult for enough blood to flow through your arteries, causing problems throughout your body, particularly your heart and brain. This can be fatal.
High cholesterol typically doesn't cause any symptoms. In the vast majority of cases, the only true symptoms it may cause are emergency events. For instance, a heart attack or stroke can result from the damage caused by high cholesterol over time. These events typically don’t occur until high cholesterol leads to the formation of plaque in your arteries. Plaque can narrow your arteries, letting less blood to pass through. The formation of plaque fundamentally changes the make-up of your arterial lining, leading to serious complications.
There are no direct symptoms in the vast majority of cases, so a blood test is the only way to know whether or not your cholesterol is too high. This is typically defined as having a total blood cholesterol level above 240 milligrams/deciliter (mg/dL). Ask your doctor to have a cholesterol test after you turn 20 and then get your cholesterol rechecked every four to six years. Your doctor may also suggest you have your cholesterol checked more frequently if you have a family history of high cholesterol, if you smoke, have high blood pressure, or are overweight.
As noted repeatedly above, the vast majority of people have no idea they have hypercholesterolemia in the absence of blood testing. However, in rare cases, there are familial syndromes where the cholesterol levels are extremely high (familial hypercholesterolemia). These people have cholesterol levels of 300 mg/dL or higher. Such people may exhibit symptoms from high cholesterol that are due to deposits of cholesterol (known as xanthomas) over their tendons or under their eyelids (known as xanthalasmas). However, while high cholesterol in general is an enormous problem affecting a large portion of the US population, familial hypercholesterolemia affects only about one in 500 people.
Nonetheless, it’s important to understand the symptoms of the major complications of the common type of high cholesterol so that you can receive prompt treatment.
Coronary Artery (Heart) Disease
Symptoms of heart disease may be different for men or women. However, coronary heart disease remains the number one killer of both genders in the United States. The most common symptoms include:
- angina (chest pain)
- extreme fatigue
- shortness of breath
- pain in the neck, jaw, upper abdomen or back
- numbness or coldness in your extremities
The buildup of plaque caused by having high cholesterol can put you at serious risk of having an event in which the blood supply to an important part of your brain is suddenly cut off. A stroke occurs when the blood supply to part of your brain is cut off or reduced. The brain is then deprived of oxygen, and death of that brain tissue occurs quickly if blood supply is not restored very quickly.
A stroke is a medical emergency. It’s important to act fast and seek medical treatment if you or anyone you know experiences the symptoms of a stroke.
Signs of a stroke include:
- sudden loss of balance and coordination
- sudden dizziness
- facial asymmetry (drooping eyelid and mouth on just one side)
- inability to move, particularly affecting just one side of the body
- slurring words
- numbness in the face, arm, or leg, especially on one side of the body
- blurred vision, blackened vision, or double vision
- sudden severe headache
The arteries that supply the heart with blood can slowly narrow due to the buildup of plaque. This process, called atherosclerosis, happens slowly over time and has no symptoms. Eventually, a piece of the plaque can break off. When this happens, a blood clot forms around the plaque and can block blood flow to the heart muscle, depriving it of oxygen and nutrients. This deprivation is called ischemia. When the heart becomes damaged or part of the heart begins to die due to the lack of oxygen, it’s called a heart attack. The medical term for a heart attack is myocardial infarction.
According to the American Heart Association, someone in the United States has a heart attack roughly every 34 seconds.
Signs of a heart attack include:
- tightness, squeezing, fullness, pain or aching in the chest or arms
- difficulty breathing
- anxiety or an a feeling of impending doom
- nausea, indigestion, or heartburn
- excessive fatigue
A heart attack is a medical emergency. It is likely to be either fatal or at least irreversible if it is not definitively treated in the first several hours after it occurs. It’s important to act fast and seek medical treatment if you or anyone you know experiences the symptoms of a heart attack.
Peripheral Arterial Disease
Peripheral artery disease (PAD) can occur when plaque builds up in the walls of the arteries, blocking the blood flow in the arteries that supply blood to the kidneys, arms, stomach, legs, and feet.
Symptoms of early PAD may include:
- pain in the legs during activity or exercise (intermittent claudication)
- discomfort in the legs and feet
Eventually, the PAD progresses and symptoms occur more frequently and even occur when you are at rest. Later symptoms that may occur because of reduced blood flow include:
- thinning, paleness, or shininess on the skin of the legs and feet
- tissue death caused by lack of blood supply (gangrene)
- ulcers on the legs and feet that don’t heal or heal very slowly
- leg pain that doesn’t go away when at rest
- burning in your toes
- leg cramps
- thick toenails
- toes that turn blue
- reduced hair growth on the legs
- a decrease in the temperature of your lower leg or foot, compared to the other leg
People with PAD have a higher risk of having a heart attack, stroke, or limb amputations.
In the vast majority of cases, high cholesterol doesn’t cause any visible symptoms. This is a big reason why it’s so important to eat healthily, exercise, and regularly monitor your cholesterol levels by getting them routinely checked at the doctor’s office.
The American Heart Association recommends having your cholesterol levels checked every four to six years if you are a healthy adult over the age of 20. You may need to have your cholesterol checked more often if you are at an increased risk of high cholesterol. You may also need more frequent cholesterol checks if you have a family history of cholesterol problems or heart attacks at a young age, especially if they’ve affected your parents or grandparents.
High cholesterol is very easy to diagnose with a blood test called a lipid panel. Your doctor will take a sample of blood and send it to a laboratory for analysis. Your doctor will ask that you do not eat or drink anything (fast) for at least 12 hours prior to the test.
A lipid panel measures your total cholesterol, HDL cholesterol, LDL cholesterol, and triglycerides. The Centers for Disease Control and Prevention (CDC) defines the following blood cholesterol levels as "desirable", or what you should aim for.
- total cholesterol: less than 200 mg/dL
- LDL cholesterol: less than 100 mg/dL
- HDL cholesterol: 40 mg/dL or higher
- triglycerides: less than 150 mg/dL
Your total cholesterol is generally considered “borderline high” if it’s between 200 and 239 mg/dL. It’s considered “high” if it’s above 240 mg/dL.
Your LDL cholesterol is generally considered “borderline high” if it’s between 130 and 159 mg/dL. It’s considered “high” if it’s above 160 mg/dL.
Your HDL cholesterol is generally considered “poor” if it’s below 40 mg/dL.