What
is High Cholesterol?
The normal cholesterol levels for humans are said as:
Total cholesterol : below 200 mg/dL
LDL cholesterol : below 130 mg/dL
HDL cholesterol : 50 mg/dL or higher
But when total & LDL cholesterol rises and HDL cholesterol falls, there is a chance of high cholesterol.
High cholesterol level arises when:
Total cholesterol : 240 mg/dL or higher
LDL cholesterol : 160 mg/dL or higher
HDL cholesterol : below 40 mg/dL
- Due to high cholesterol, our blood vessels may develop some fatty deposits.
Eventually, these deposits grow, making it difficult for enough blood to flow
through our arteries. Sometimes, these deposits can break suddenly and form a
clot that causes a heart attack or stroke.
- High
cholesterol can be inherited, but it's often the result of unhealthy lifestyle
choices, which make it preventable and treatable. A healthy diet, regular
exercise and sometimes medication can help reduce high cholesterol.
- Most
of the cholesterol in the blood is carried by proteins called low density
lipoproteins or LDL. This is known as bad cholesterol because it combines
with other substances to clog the arteries. A diet high in saturated fats and
trans fats tends to raise the level of LDL cholesterol. For most people, an LDL
score below 100 is healthy, but people with heart disease may need to take
medications to lower their LDL.
What
Boosts Our Risk?
Several
factors can make us more likely to develop high cholesterol:
- A diet high in saturated fats and
cholesterol
- A family history of high cholesterol
- Being overweight or obese
- Getting older
Why
High Cholesterol Matters?
High
cholesterol is one of the major risk factors for coronary artery disease, heart
attacks, and strokes. It also appears to boost the risk of Alzheimer's disease.
As we saw earlier, high cholesterol leads to a buildup of plaque that narrows
the arteries. This is dangerous because it can restrict blood flow. If the
blood supply to a part of the heart or brain is completely cut off, the result
is a heart attack or stroke.
Why
is High Cholesterol Dangerous?
Elevated
cholesterol levels are one of the risk factors for heart disease, stroke, and peripheral artery disease.
The mechanism involving cholesterol in all three diseases is the same; plaque
buildup within arteries decreases blood flow affecting the function of the
cells and organs that these blood vessels supply.
Atherosclerotic heart disease or narrowed
coronary arteries in the heart can cause the symptoms of angina,
when the heart muscle is not provided with enough oxygen to function.
Decreased
blood supply to the brain may be due to narrowed small arteries in the brain or
because the larger carotid arteries in the neck may become blocked. This can
result in a Transient Ischemic Attack (TIA)
or stroke.
Peripheral
artery disease describes gradual narrowing of the arteries that supply the
legs. During exercise,
if the legs do not get enough blood supply, they can develop pain,
called claudication.
Other
arteries in the body may also be affected by plaque buildup causing them to
narrow, including the mesenteric arteries to the intestine and the renal
arteries to the kidney.
Symptoms of High Cholesterol
High
cholesterol does not exhibits any symptoms. But it does cause damage deep within
the body. Over time, too much cholesterol may lead to a buildup of plaque
inside the arteries. Known as atherosclerosis, this condition narrows the space
available for blood flow and can trigger heart disease.
A
person with high cholesterol levels often has no signs or symptoms, but routine
screening and regular blood tests can help detect high levels. A person who
does not undergo testing may have a heart attack without warning, because they
did not know that they had high cholesterol levels. Regular tests can help to
reduce this risk.
Many
people don’t even realize they have high cholesterol until they develop serious
complications, such as a heart attack or stroke.
That’s
why routine cholesterol screening is important. If you’re age 20 years or
older, ask your doctor if you should have routine cholesterol screening. Learn how this
screening could potentially save your life.
Causes of High Cholesterol
High
cholesterol is a significant risk factor for coronary heart disease and a
cause of heart attacks.
A
build-up of cholesterol is part of the process that narrows arteries, called atherosclerosis. In atherosclerosis, plaques
form and cause restriction of blood flow.
Reducing
the intake of fat in the diet helps to manage cholesterol levels. In
particular, it is helpful to limit foods that contain:
- Cholesterol: This is present in animal
foods, meat, and cheese.
- Saturated fat: This occurs in some
meats, dairy products, chocolate, baked goods, deep-fried, and processed foods.
- Trans fats: This occurs in some fried
and processed foods.
- Unhealthy eating habits, such as eating
lots of bad fats: One type, saturated fat, is found in some meats, dairy
products, chocolate, baked goods, and deep-fried and processed foods. Another
type, trans fat, is in some fried and processed foods. Eating these fats can
raise your LDL (bad) cholesterol.
- Excess weight or obesity can also lead to higher blood LDL
levels. Genetic factors can contribute to high cholesterol. People with the
inherited condition familial hypercholesterolemia have very high LDL levels.
Other
conditions that can lead to high cholesterol levels, include:
- diabetes
- liver or kidney disease
- polycystic ovary syndrome
- pregnancy and other conditions that
increase levels of female hormones
- underactive thyroid gland
- drugs that increase LDL cholesterol and
decrease HDL cholesterol, such as progestins, anabolic steroids, and
corticosteroids
What
Can Raise Risk of High Cholesterol?
A
variety of things can raise our risk for high cholesterol:
- Age: Our cholesterol levels tend to
rise as we get older. Even though it is less common, younger people, including children and teens, can
also have high cholesterol.
- Heredity: High
blood cholesterol can run in families.
- Weight: Being
overweight or having obesity raises our cholesterol level.
- Race: Certain races may have an
increased risk of high cholesterol. For example, African Americans typically
have higher HDL and LDL cholesterol levels than whites.
Risk Factors for High Cholesterol
Factors
that can increase our risk of bad cholesterol include:
- Poor diet: Eating saturated
fat, found in animal products, and trans fats, found in some commercially baked
cookies and crackers and microwave popcorn, can raise our cholesterol level.
Foods that are high in cholesterol, such as red meat and full-fat dairy
products, will also increase our cholesterol.
- Obesity: Having
a body mass index (BMI) of 30 or greater puts us at risk of high cholesterol.
- Lack of exercise:
Exercise helps boost our body's HDL, or "good," cholesterol but lack of exercise increases the size of the particles that makes up LDL, or "bad,"
cholesterol, which is harmful.
- Smoking:
Cigarette smoking damages the walls of our blood vessels, making them more
prone to accumulate fatty deposits. Smoking might also lower our level of HDL,
or "good," cholesterol.
- Age: Because our body's chemistry
changes as we age, our risk of high cholesterol climbs. For instance, as we
age, our liver becomes less able to remove LDL cholesterol.
- Diabetes: High
blood sugar contributes to higher levels of a dangerous cholesterol called
very-low-density lipoprotein (VLDL) and lower HDL cholesterol. High blood sugar
also damages the lining of our arteries.
What
Health Problems can High Cholesterol Cause?
If we
have large deposits of plaque in our arteries, an area of plaque can rupture
(break open). This can cause a blood clot to form on the surface of the
plaque. If the clot becomes large enough, it can mostly or completely block
blood flow in a coronary artery.
If the
flow of oxygen-rich blood to our heart muscle is reduced or blocked, it can
cause angina
(chest pain) or a heart attack.
Plaque
also can build up in other arteries in our body, including the arteries that
bring oxygen-rich blood to our brain and limbs. This can lead to problems such
as carotid artery disease, stroke, and peripheral arterial disease.
Diagnosis
A
blood test to check cholesterol levels — called a lipid panel or lipid profile
— typically reports:
- Total cholesterol
- LDL cholesterol
- HDL cholesterol
- Triglycerides — a type of fat in the
blood
For
the most accurate measurements, don't eat or drink anything (other than water)
for nine to 12 hours before the blood sample is taken.