For the first time in decades, the average American life expectancy dropped. In a report from late last year, the National Center for Health Statistics showed that Americans could expect to live for 78.8 years in 2015, which is a 0.1 decrease from the prior year.

“A .01 increase is huge,” Dr. Petter Muenning told The New York Times. “Life expectancy increases, and that’s very consistent and predictable, so to see it decrease, that’s very alarming.”

Read: Drink Coffee And Shop: 5 Ways For Women To Increase Their Lifespan, According To Science

The last time it declined was in 1993, in large part due to the tremendous increase in HIV-related deaths. But, why has it dropped again? This time there’s not a single factor, but rather many health problems that researchers are pointing to, as seen in the infographic below.

This infographic shows many reasons behind why Americans aren’t living longer. Photo courtesy of NowSourcing,Inc.

In the U.S., health problems are worsening across the board. Death rates rose for 8 out of 10 leading causing of death: heart disease, chronic lower respiratory disease, unintentional injuries, stroke, Alzheimer’s disease, diabetes, influenza and pneumonia, kidney disease, and suicide.

Compared to other countries, we are far behind in life expectancy. Japan takes the number one spot with an average life expectancy of 83.7 years, and the U.S. ranks 28th, behind countries like Switzerland, Spain, and Australia.

One suspected reason is because of our alarmingly high rates of obesity. Only 3.3 percent of Japan’s population is obese compared to 33.7 percent in the U.S. Being obese impacts nearly every aspect of your health and increases the risk of deadly diseases like diabetes, heart disease, and some cancers.

Income also plays a role in life expectancy. Richer Americans live longer than the poor and middle class, according to data from the National Academies of Science, Engineering, and Medicine. Additionally, wage inequality is only getting worse.

The decreased life expectancy isn’t consistent, but there is still a reason to be startled by it.

“If a year from now if this situation continues," Dr. Jiaquan Xu told The New York Times, “it’s definitely a problem for public health.”

See also: How Long Will You Live? Life Expectancy Depends On Your Neighborhood

How Do We Live Longer? 5 Ways Scientists Think We'll Be Able To Increase Life Expectancy