U.S. adults have had about 14 million major medical conditions caused by smoking, a new government study concludes. This includes about 7.5 million adults who suffer from smoking-related chronic obstructive pulmonary disease.

Smoking is also linked to 2.3 million cases of heart attack, 1.3 million cases of cancer, 1.2 million cases of stroke and 1.8 million cases of diabetes, HealthDay reports.

The findings are published in JAMA Internal Medicine.

“For each annual death, there are 15 to 20 people living with major disease caused by smoking,” said senior study author Terry Pechacek of the Centers for Disease Control and Prevention. “Smoking not only will kill you, it will damage your health and make your life worse.”

He noted the findings about diabetes were of particular concern. “We’ve known for quite a while that smoking makes diabetes outcomes worse, and diabetics who smoke are really placing themselves at great risk,” Pechacek said. “But if people smoke who have a tendency toward diabetes, are pre-diabetic, they are at a much higher risk of progressing to full diabetes. Smoking causes diabetes and makes it much worse. People are not aware of that.”

As discouraging as the findings are, Pechacek says they could have been much worse if the smoking rate had not declined in recent years. “Millions and millions more people would have suffered and died, or still be suffering with disease, if we hadn’t cut the smoking rate,” he said. “The message is clear. Quit, quit as early in life as possible, and don’t be afraid to talk to your friends and family who are still smoking.”