High Cholesterol Levels – Definition and Diagnosis

Cholesterol Is A Type Of Fat

Cholesterol is a substance known as a lipid, a type of fat. Most of the body’s supply of cholesterol is produced in the liver, but some is derived from food (eg. eggs and meat). In simple terms, there are two types of cholesterol: a ‘good’ type called high density lipoprotein (HDL) and a ‘bad’ type called low density lipoprotein (LDL). Triglyceride is another lipid, closely related to cholesterol, whose levels, like those of HDL and LDL, should also be monitored.

High Cholesterol Levels

A high level of cholesterol in the blood is a condition known as hypercholesterolemia. This is a form of hyperlipidemia (also known as lipemia, lipidemia, lipoidemia, hyperlipoidemia) which means simply: excess lipids in the bloodstream. The other type of hyperlipidemia, in addition to hypercholesterolemia, is called hypertriglyceridemia which means: excess levels of triglycerides in the blood.

What Constitutes A High Cholesterol Count?

Cholesterol levels in the blood (serum cholesterol) are most accurately measured by taking a blood sample after the patient has fasted for 12 hours.

Optimum Serum Cholesterol

For a middle-aged person, the optimal range of total cholesterol is 115-200 mg/dL (3-5.2 mmol/L). If total cholesterol exceeds 200 mg/dL (5.2 mmol/L), the doctor is likely to take a close look at the patient’s levels of HDL, LDL and triglycerides, since it is the proportion of LDL-cholesterol to HDL-cholesterol, and triglyceride level which predicts the likelihood of adverse health consequences such as atherosclerosis.

US Diagnosis Of High Cholesterol

– Desirable: Less than 200 mg/dL
– Borderline High Risk: 200–239 mg/dL
– High Risk: 240 mg/dL and over

UK Diagnosis Of High Cholesterol

– Ideal level: less than 5mmol/l.
– Mildly high cholesterol: between 5 to 6.4mmol/l.
– Moderately high cholesterol level: between 6.5 to 7.8mmol/l.
– Very high cholesterol: above 7.8mmol/l.

High Cholesterol – Health Risk Assessment

Note that the significance of a specific cholesterol count cannot be assessed without taking into account the ratio between good HDL and bad LDL cholesterol, the triglyceride count, and the presence/absence of other cardiovascular risks, such as smoking, diabetes, raised blood pressure (hypertension), and any likelihood of inherited or familial hypercholesterolemia due to a genetic defect. For example, it is possible for a patient to have a high level of “total” cholesterol yet still have a relatively low cardiovascular risk because of low LDL cholesterol, an absence of other lifestyle-risk factors or because their family history is free from coronary disease. On the other hand, hypertriglyceridemia (high levels of triglycerides) has been linked to atherosclerosis, even when cholesterol levels are normal.

When Are HDL Cholesterol Levels Too High?

In America, HDL is assessed as follows:

– Less than 40 means you’re at higher risk for heart disease.
– 60 or higher reduces your risk of heart disease.

When Are LDL Cholesterol Levels Too High?

In America, LDL is assessed as follows:

– Less than 100 mg/dL (Optimal)
– 100 to 129 mg/dL (Near Optimal/ Above Optimal)
– 130 to 159 mg/dL (Borderline High)
– 160 to 189 mg/dL (High)
– 190 mg/dL and above (Very High)

When Are Triglyceride Levels Too High?

In America, tryglyceride levels are assessed as follows:

– Less than 150 mg/dL (Normal)
– 150–199 mg/dL (Borderline-high)
– 200–499 mg/dL (High)
– 500 mg/dL or higher (Very high)

Diagnosis Of High Cholesterol

After fasting for 12 hours, during which only water should be consumed, a patient gives a blood sample which is then used to measure the level of cholesterol, LDL-cholesterol, HDL-cholesterol and triglyceride in the bloodstream. Typically cholesterol levels rise during pregnancy and drop significantly during serious illness.

Evidence Of Vascular Disease

If the cholesterol count is high, the doctor may seek evidence of cardiovascular disease by measuring the pulse, blood pressure, listening to the heart, and other large arteries, monitoring kidney function with a blood test and arranging an electrocardiogram (ECG).

When to Have Your Cholesterol Count Checked?

Ideally, men aged 35 and older and women aged 45 and older should have their cholesterol measured annually, although this regularity may vary according to your cholesterol level and what other health risk factors you have.