MILWAUKEE (CBS 58) -- Questions surrounding Luigi Mangione's motives have launched a conversation around chronic pain.

An ailment that millions of Americans deal with daily.

"On the outside, people often look normal it's hard to see what's going on the inside," said Dr. Stauss, Pain Physicians of Wisconsin.

According to the Centers for Disease Control and Prevention, more than 20% of Americans live with chronic pain.

Dr. Thomas Stauss, with Pain Physicians of Wisconsin, says it's an unappreciated illness since most people cannot see patients' pain.

"It's very common for patients who are struggling with chronic pain to really feel frustrated that no one understands how they feel," said Dr. Stauss.

He says long-term chronic pain can take a toll on the patient's mental health.

"Depression, anxiety, suicide risk is up we talked about opioid dependence, mental status changes sometimes as a result of medications," Dr. Stauss explained.

Dr. Stauss says one of the biggest problems for providers and patients is coverage.

"Ways of coverage or not covering and it can lead to a lot of stress and frustration on the provider side as well as the patient side and it is a growing problem," said Dr. Stauss.

However, he says there are multiple ways to help the pain.

"You can come at it in multiple different angles, sometimes medication, exercise, diet changes, pain coping strategies, and sometimes some of the interventional nerve blocks, injectables, or even surgery."