http://www.healthfinder.gov/prevention/
See the above link for a lot of general health tips and an explanation of every single thing that you can get checked out to make sure you're as healthy as you think you are.
In general, there are just a few things to keep in mind:
- Be physically active and make healthy food choices.
- Get to a healthy weight and stay there. Balance the calories you take in from food and drink with the calories you burn off by your activities.
- Be tobacco free. For tips on how to quit, go to http://www.smokefree.gov. To talk to someone about how to quit, call the National Quitline: 1-800-QUITNOW (784-8669).
- If you drink alcohol, have no more than one drink per day. A standard drink is one 12-ounce bottle of beer or wine cooler, one 5-ounce glass of wine, or 1.5 ounces of 80-proof distilled spirits.
Lastly, visit your primary care doctor at least once every other year! Always tell them about any changes in your body/health/senses. If something runs in your family or if you're worried about something, ask them about how to check for it.