While higher levels of LDL are harmful, the higher the levels of HDL within the normal range, the more beneficial it is to your health. Maintaining a higher count of HDL cholesterol in the blood is good for a healthy lipid profile and a healthy heart.

This is because HDL carries the excess of low-density lipoproteins (LDL), the bad cholesterol from the blood in the arteries to the liver for excretion through the bile into the intestine.

It even disintegrates the atheroma that could be formed on the inner walls of the arteries and carry it to the liver for excretion.

HDL cholesterol test levels

Your doctor advises you to undergo the blood test for cholesterol, which is referred to as the lipid profile or the lipid panel. It is done on an empty stomach after you have fasted for 9 to 12 hours. It gives you the blood values of the following:

  • Total blood (or serum) cholesterol
  • HDL (good) cholesterol
  • LDL (bad) cholesterol
  • Triglycerides

The values are expressed in two types of measuring units:

  • mg/dL (milligram per deciliter) followed in America  and some other countries
  • mmol/L ((millimoles per liter) followed in Canada, the United Kingdom, and other European countries

These HDL cholesterol (HDL-C) values tell you the amount of cholesterol carried by the high-density lipoprotein particles. The HDL particles differ in size and can be small or large.

Below is a chart showing the normal and the low undesirable HDL levels.

Normal levels   – more than 60 mg/dL – lower risk of heart disease

Low in men        — less than 40 – a risk factor for heart disease

Low in women   – less than 50 – risk factor for heart disease

These values are in the American units. For their equivalent in British or European measurements, this post offers to convert the measurement units.

Based on results of the Framingham Heart Study, the risk of heart attack increases by about 25 percent for every 5 mg/dl (0.13 mmol/L) drop in blood levels of HDL cholesterol.

Normal HDL levels of 60 mg/dl are healthy and your risk of a heart disease and stroke stands low. It is established that HDL does offer a significant amount of protection to your heart at its healthy levels.

Secondly, raised HDL levels are associated with low levels of very low-density lipoprotein cholesterol (VLDL) and low triglyceride (TG) levels. This again is another factor how healthy HDL levels protect your heart.

Precautions before doing the test

Do not test for HDL cholesterol in the following circumstances because HDL is typically low.

  • During an acute illness. Do the test six weeks after the illness has subsided.
  • Immediately after an heart attack
  • During stress (like following a surgery or an accident).

HDL levels and cardiovascular disease risk

For adults

  • Low HDL numbers below 40 mg/dL in men and below 50 mg/dl in women can be an independent factor for coronary heart disease not influenced by any risk factors including LDL levels.
  • HDL-C  levels between 40-50 mg/dL (1.0-1.3 mmol/L) for men and between 50-59 mg/dl (1.3-1.5 mmol/L) for women carry an average risk of heart disease.
  • However, according to experts, high levels of HDL cholesterol above 60 mg/dL or 1.5 mmol/L do not appear to offer any added benefits. Its maximum benefits are accrued at the optimal levels
  • Furthermore, at very high levels beyond 2.3mmol/l or 90 to 100 mg/dL, HDL starts to behave like LDL and increases your risk of heart disease.

For children, teens and young adults:

  • With HDL-C less than 40 mg/dL (1.04 mmol/L) there is an increased risk of heart disease that is independent of other risk factors, including the LDL-C level.
  • With HDL-C between 40 and 45 mg/dL (1.04-1.17 mmol/L), the risk is borderline.
  • With HDL-C greater than 45 mg/dL (1.17 mmol/L) risk is minimal

It is important to remember that cholesterol isn’t the only factor contributing to a high risk of heart disease.  There are many other factors that increase your heart attack risk such as diabetes, hypertension, smoking and more.

How often should you check your cholesterol numbers?

The American Heart Association recommends that you should check your blood cholesterol levels every 5 years after the age of 20.

After the age of 35 years, you should check every 6 months or every year, depending on the risk factors you carry.

Children, too, are advised to undergo the cholesterol test at specific age group depending on the risk factors they carry such as a family history, obesity, etc.

This post on the cholesterol levels by age describes it all and why.

How to improve low HDL cholesterol levels?

Low HDL numbers need to be corrected. You can increase the HDL values with drugs or without drugs, which is the preferred method.