Your blood cholesterol level can help indicate whether you’re at risk for heart attack, stroke, or other types of cardiovascular disease.

You calculate total cholesterol by adding up the following numbers:

Your cholesterol ratio is calculated by dividing your total cholesterol by your HDL number.

For instance, if your total cholesterol is 180 milligrams per deciliter (mg/dL) of blood and your HDL is 82 mg/dL, your cholesterol ratio is 2.2.

According to StatPearls, you should try to keep your cholesterol ratio below 5, with the ideal cholesterol ratio being 3.5. That said, the ideal cholesterol ratios for men and women may differ.

The ideal total cholesterol level for an adult is 200 mg/dL or less.

Women typically have higher levels of HDL than men. The ideal HDL level is at least 40 mg/dL in men and at least 50 mg/dL in women. This means that men and women may want to aim for cholesterol ratios of 5 and 4, respectively.

A 2019 study looked at the relationship between the cholesterol ratio and acute myocardial infarction (AMI) in Swedish women in their 50s. AMI is another term for heart attack. Data was collected between 1995 and 2000.

The researchers found that women with a cholesterol ratio of 3.5 or below had the lowest risk of AMI. In comparison to women with a cholesterol ratio of 3.5 or below:

  • women with a cholesterol ratio of 3.5 to 4.0 were 14 percent more likely to experience AMI
  • women with a cholesterol ratio of 4.0 to 5.0 were 46 percent more likely to experience AMI
  • women with a cholesterol ratio of 5.0 or above were 89 percent more likely to experience AMI

HDL, or good cholesterol, carries about 25 to 33 percent of the free cholesterol that’s circulating in your body back to your liver. Afterward, the liver moves the LDL out of your body, which helps prevent it from clogging your arteries.

On the other hand, LDL, or bad cholesterol, transports cholesterol to your arteries. It can lead to a buildup of plaque in the arteries, resulting in poor blood flow and a condition known as atherosclerosis.

Cholesterol, even the bad kind, still has its benefits. Your body needs cholesterol for many important functions, such as producing bile acids or hormones such as estrogen and testosterone. However, your liver naturally produces enough cholesterol that you don’t have to worry about getting it through your diet.

Optimal HDL levels are over 40 mg/dL for men and over 50 mg/dL for women, according to Germany’s Institute for Quality and Efficiency in Health Care.

An optimal LDL level is under 100 mg/dL, according to the Centers for Disease Control and Prevention (CDC).

Mathematically speaking, you can improve your cholesterol ratio by either reducing your total cholesterol level or increasing your HDL level. Here are a few tips for improving your cholesterol ratio.

Eat more soluble fiber

Eating more fiber is good for your overall cardiovascular health. Soluble fiber in particular may help lower your blood cholesterol levels, according to research. Get more soluble fiber in your diet by choosing foods like:

Eat fewer unhealthy fats

Avoid or limit foods that contain trans fats or certain saturated fats, like the kind found in processed foods. They’re associated with higher levels of total cholesterol and LDL, and lower levels of HDL.

Exercise

Exercise, and aerobic exercise in particular, may help to raise your HDL levels, according to research. Incorporate some of the following aerobic activities into your regular workout routine:

Quit smoking

According to studies, smoking cigarettes may increase your LDL and total cholesterol levels and decrease your HDL levels. If you currently smoke, get help to quit.

Consider statins

These medications lower levels of LDL and total cholesterol in your body. They may also help boost your HDL levels.

Examples of statins include:

According to the American Heart Association (AHA), adults who may benefit from statins include people:

  • with a history of cardiovascular disease caused by atherosclerosis
  • with an LDL level of 70–189 mg/dL and a 10-year risk of cardiovascular disease — caused by atherosclerosis — that exceeds 5 percent
  • with an LDL level over 190 mg/dL
  • who have diabetes and are 40–75 years old

Speak with a doctor about whether statins are right for you.

Taking these medications is usually a lifelong commitment. Safely discontinuing their use requires you to work closely with your doctor.

Your cholesterol ratio clarifies the picture of your risk of heart disease.

A 2020 study looked at the effect of different cholesterol measurements on people’s risk of atherosclerotic cardiovascular disease. The researchers found that people with a higher cholesterol ratio despite low LDL or non-HDL levels were still at increased risk of atherosclerotic cardiovascular disease.

People with a higher cholesterol ratio and low LDL or non-HDL levels were also at a greater risk of atherosclerotic cardiovascular disease when compared to people with a lower cholesterol ratio and high LDL or non-HDL levels.

This suggests that clinicians should prioritize the cholesterol ratio over just the LDL and non-HDL cholesterol levels when assessing cardiovascular risk.

However, the ratio alone isn’t enough to assess what treatment will be best if your risk is high. A doctor will still take your total cholesterol into account when determining the correct mix of diet, exercise, and medication to bring your numbers into the desirable range.