Smoking is a lot more dangerous for you than previously thought, according to a new report from the U.S. Surgeon General.
The 980-page report now links cigarettes with a number of diseases, including diabetes, arthritis and liver cancer.
It can also hurt your immune system and cause birth defects, and exposure to second-hand smoke can cause a stroke.
The report comes exactly 50 years after the surgeon general first warned about the dangers of smoking.
"The clock is ticking," acting Surgeon General Borish Lushniak warned. "We can't wait another 50 years."