Diabetes can make people more prone to easy or unexpected bruising in several ways:
- High blood sugar can cause blood vessel damage
- Needles and lancets can cause injury at the puncture site
- Peripheral neuropathy can damage nerves, dulling your ability to notice injury
- Diabetes impacts collagen production, which thins the skin
People with diabetes may be slower to heal from cuts, too. “People with diabetes can experience delayed wound healing for several reasons,” says Joshua J. Neumiller, PharmD, CDCES, the president-elect of healthcare and education for the American Diabetes Association. “If people have hyperglycemia (high blood glucose), high blood pressure, or high cholesterol for a long period of time, this can lead to blood vessel damage and poor circulation (blood flow).”
“In the case of people who bruise due to injection of medications or through glucose monitoring (with fingersticks or CGM), it is important to use new needles and lancets each time and rotate injection and testing sites,” says Dr. Neumiller.
“Neuropathy is nerve damage that leads to changes in the ability to feel one’s body parts,” says Deena Adimoolam, MD, an endocrinologist for Mount Sinai Health System in New York City. “Due to this loss of sensation, people with neuropathy may not realize they have injured their body part, which may lead to unexplained bruising.”
“When blood glucose is elevated, it can interact with collagen, leading to skin changes in people with diabetes,” says Neumiller.