Smoking cigarettes, weed, doing drugs or drinking beer/ale/booze - ANY of these can interrupt blood flow to your penis resulting in diminished sex drive & cause erectile dysfunction or impotence.
Stress, anxiety, depression, crappy diet, lack of exercise & some medications can also cause malfunction at the junction.
Eventually, smoking can cause mouth, tongue, throat, gum, lung or pancreatic cancer.
Alcohol can cause cirrhosis of the liver - of which there is no cure.
Just make sure your Life Insurance Policy premiums are paid up to date so your family won't get stuck with your final funeral expenses.