First on our list: nail-biting. When you chew, bacteria under your nails can enter your mouth.
Next up: rubbing your eyes. Doing it too much can thin out the corneas.
Also, wearing contact lenses too long: As many as 67 percent of people who wear them do it. Not changing your lenses can damage your corneas.
"You can also change the shape of your cornea, and that will start distorting, your vision," said Dr. Sharon Bergquist
Loud music is a vice enjoyed by many, but it can be dangerous. Twenty percent of rock musicians have permanent hearing loss.
Wearing high heels all the time can cause bunions, hammertoe, varicose veins and more.
"The inner part of your knee gets a little more wear and tear, and you can get premature arthritis in your knee," said Bergquist.
Another no-no: eating too fast. It takes the brain about 20 minutes to recognize the stomach is full, so it's easy to overeat.
And skimping on sleep: Getting less than six hours a night can double the risk of heart attack and stroke.
And vice number seven to avoid, and maybe the most dangerous: constant sitting. Women who sit more than six hours a day have a 37 percent higher death rate than those who sit for less than three.
Whatever your weakness, remember, moderation is key.