A high blood cholesterol level increases your risk of coronary artery disease. Lower cholesterol is usually better, but in rare cases having a very low level of low-density lipoprotein (LDL, or "bad") cholesterol or a very low total cholesterol level has been associated with some health problems.

Doctors are still trying to find out more about the connection between low cholesterol and health risks. There is no consensus on how to define very low LDL cholesterol, but LDL would be considered very low if it is less than 40 milligrams per deciliter of blood.

Although the risks are rare, very low levels of LDL cholesterol may be associated with an increased risk of:

• Cancer
• Hemorrhagic stroke
• Depression
• Anxiety
• Preterm birth and low birth weight if your cholesterol is low while you're pregnant

The potential risk of lowering LDL cholesterol to very low levels has not been confirmed, and its association with certain health risks is still under debate.

Recent trials using novel treatments to lower cholesterol have reached extremely low cholesterol values with no increased risk for major side effects, but the follow-up was relatively short.

In some cases it is not clear if low cholesterol causes the health problem or if it's the other way around. For example, people with depression may have low cholesterol levels, but it has not been proved that lowering cholesterol with statin therapy causes depression.

However, the benefits of lowering total and LDL cholesterol have been demonstrated extensively, particularly in individuals with heart disease or at high risk of heart disease or strokes.

If you're concerned about your cholesterol level, consult your doctor. If you're taking statins, don't stop without first consulting your doctor. He or she can determine the cholesterol range most appropriate for you.