Malfunctioning glucose trackers made by Abbott Diabetes Care have been linked to more than 700 severe adverse events and seven potential deaths, the Food and Drug Administration (FDA) and Abbott said.

The medical device manufacturer first issued a public statement and sent a letter notifying those possibly impacted on Nov. 24, saying it had initiated a "medical device correction" for certain FreeStyle Libre 3 and FreeStyle Libre 3 Plus sensors. The FDA issued an early alert on Dec. 2, a type of notice sent out when a company removes or corrects a product for high safety risks before the FDA can determine if a formal recall is required.

Some FreeStyle Libre 3 sensors may provide incorrect low glucose readings, prompting incorrect treatment decisions for people with diabetes. When a diabetic's blood sugar (AKA glucose) is low, they may do things to make it higher or prevent it from getting lower, like skipping or delaying an insulin dose (which is used to lower blood sugar) or eating too many carbohydrates, which raises glucose in the body.

These treatment decisions based on incorrect readings could cause blood sugar to be improperly controlled, resulting in serious complications and health risks, including injury or death. Some common complications of mismanaged blood sugar in diabetics include diabetic ketoacidosis, heart disease or attack, stroke, kidney, nerve or eye damage, and increased risk of infection.

The issue involves approximately three million Libre 3 and Libre 3 Plus sensors in the U.S., about half of which are estimated to have expired or already been used. Globally, Abbott has received reports of 736 severe adverse events (57 in the U.S.) and seven deaths (none in the U.S.) potentially associated with this issue.

"Abbott has identified and resolved the cause of the issue, which relates to one production line among several that make Libre 3 and Libre 3 Plus sensors," the company said in a press release shared with USA TODAY. "The company continues to produce Libre 3 and Libre 3 Plus sensors to fulfill replacement and new orders and does not expect significant supply disruptions."

Here's what to know.

Which Abbott Diabetes Care products are impacted?

Only certain FreeStyle Libre 3 and FreeStyle Libre 3 Plus Continuous Glucose Monitoring Systems are impacted by the issue. FreeStyle Libre 3 readers and mobile apps are not impacted.

No other Libre products (FreeStyle Libre 14-day, FreeStyle Libre 2, FreeStyle Libre 2 Plus, or FreeStyle Libre Pro sensors) or Abbott biowearables are affected.

• FreeStyle Libre 3 Sensor

  • Model Numbers: 72081-01, 72080-01

  • Unique Device Identifiers (UDI-DI): 00357599818005, 00357599819002

• FreeStyle Libre 3 Plus Sensor

  • Model Numbers: 78768-01, 78769-01

  • Unique Device Identifiers (UDI-DI): 00357599844011, 00357599843014

How to check your FreeStyle Libre 3 serial number

FreeStyle Libre 3 users can find their device's serial number digitally in the app or reader, or physically on the label on the bottom of the sensor applicator or carton.

To check in the FreeStyle Libre 3 app:

From the "Main Menu," select the "About" screen. You can find the sensor serial number under the "Last 3 Sensors" section.

To check in the Libre app:

In the Libre app, navigate to the bottom menu and select "Profile" and then "About." Locate the sensor serial number under the "Last 3 Sensors" section.

To check on the FreeStyle Libre 3 Reader:

In the FreeStyle Libre 3 Reader, navigate to the "Settings Menu" and select "System Status," then "System Info." Look under the "Sensor SN & Status" section.

To check on the sensor carton and label:

The serial number can be found both on the sensor carton and the label on the bottom of the sensor applicator itself.

What to do if you have an impacted FreeStyle Libre 3

Consumers can visit www.FreeStyleCheck.com to see if their sensors are affected and to get a replacement from Abbott at no charge. Notice letters were also sent to potentially impacted distributors, health care providers and customers on Nov. 24.

Consumers who are currently wearing or have a sensor that has been confirmed as potentially impacted should immediately discontinue use and dispose of it.

You can request a replacement for any potentially affected sensors on FreeStyleCheck. To do so, visit the site and select "CONFIRM SENSOR SERIAL NUMBER" and enter a valid serial number. If your sensor is potentially impacted, you will be instructed to enter your contact information so a replacement product can be sent to you at no cost.

In the meantime, consumers should use a blood glucose meter or the built-in meter in the FreeStyle Libre 3 reader to make treatment decisions when sensor readings don’t match symptoms or expectations.

Consumers can also call Abbott’s customer service at 1-833-815-4273, available from 8 a.m. to 8 p.m. ET daily, or chat with customer agents 24/7 through live chat at https://www.freestyle.abbott/us-en/support/contact-us.html.

Health care professionals and consumers can also report adverse reactions or quality problems they experienced using these devices to the FDA's MedWatch adverse event reporting program.

This article originally appeared on USA TODAY: Deaths, injuries linked to failing glucose monitors. See which ones