If you have high cholesterol, your doctor might recommend that you take a statin drug to help prevent heart disease and stroke.

For many people, statins lower high cholesterol levels effectively. Some people may experience side effects when they’re treated with these drugs. You may have heard about an increased risk of shingles from statins.

Shingles is an infection caused by varicella-zoster virus (VZV), or human herpesvirus 3. This is the same virus that causes chickenpox. Shingles is known more formally as herpes zoster.

After you’ve had chickenpox, the virus can hibernate in your body for many years. It can become active again later and cause shingles. Shingles usually appears in people aged 60 years or older.

Shingles can be very painful. Symptoms include:

It can also lead to complications, such as:

A 2014 Canadian study, published in the journal Clinical Infectious Diseases, investigated a possible link between statins and shingles.

Researchers compared 494,651 adults who had taken statins to an equal number of people who hadn’t taken those drugs. Then, they looked at how many people in each group were diagnosed with shingles. All study participants were at least 66 years old.

Results showed that the seniors who took statins had a slightly higher risk of shingles than those who hadn’t taken them. The authors suggested that statins may increase the risk of shingles by lowering immunity. Statins may also make VZV more likely to reactivate.

A 2018 study from South Korea compared 25,726 statin users with 25,726 people who don’t use the drugs. Study participants were adults ages 18 years old and up.

The researchers found that, in general, people who took statins were 25 percent more likely to develop shingles. If the statin user were more than 70 years old, they were 39 percent more likely to develop shingles.

Both the Canadian and South Korean studies took place over a period of at least 11 years.

A 2014 letter to the editor, also published in Clinical Infectious Diseases, proposed that the increased risk of shingles could be due to high cholesterol levels as opposed to the statin drugs used to treat them.

The letter writers suggested that an increased risk of shingles might also be the result of a gene variant called APOE4. This variant could affect immunity against the reactivation of VZV. People with high cholesterol are more likely to have this variant.

You can take measures to lower your risk of getting shingles. One of the best ways to avoid this disease is to get vaccinated.

The Centers for Disease Control recommends that healthy people over 50 years old get the vaccine Shingrix. This vaccine lowers your chance of getting shingles. If you get vaccinated and still get shingles, the vaccine makes your outbreak shorter and less severe.

Statins are effective drugs that help lower high cholesterol levels. Your doctor will most likely recommend statins for you based on your risk factors for heart attack or stroke. These factors include:

Talk to your doctor if you’re concerned about your risk of shingles from statin use. They can help you weigh the risks and benefits according to your individual health history. They can also help you take all of the steps you can to avoid shingles.