Get a physical.

While you're healthy is the best time to have a physical and get baseline readings on blood pressure, cholesterol and other vital statistics.

Keep copies of your baseline readings, especially if you change doctors frequently.

Develop healthy relationships.

Emotional well-being is just as critical to your overall health as exercise or diet.

Strong relationships developed now will help carry you through later, possibly more difficult, years. By the same token, unhealthy relationships only complicate matters. Consider mending or ending them.

Get enough sleep.

Sleep increases immunity, enhances carbohydrate metabolism and helps maintain mood.

Most adults need 7.5-8.5 hours of sleep a night. If you can't get that much, consider supplementing your sleep with catnaps—either 20 minutes or 1.5 hours are considered ideal nap lengths.

Exercise regularly.

Exercise increases metabolism, strengthens bones, controls insulin, improves mood and reduces blood pressure, cholesterol and weight.

Raising your heart rate for at least 30 minutes/day is ideal.

Reduce stress.

Stress wreaks havoc with cortisol levels, which may lead to diabetes, high blood pressure and heart disease.

Learn and use calming practices such as deep breathing, meditation, prayer and yoga.

Limit sun exposure.

Long-term sun exposure increases your risk of skin cancers, especially if you're fair-skinned. Too much sunlight also prematurely ages the skin.

Use sunscreen, wear a hat and limit your time outdoors at peak sun hours, between 11 a.m. and 1 p.m.

Do regular self-breast exams.

Self-breast exams are the first line of defense against breast cancer.

Women of all ages should check their breasts monthly, but closer to age 40 it's best to combine self-exams with annual mammograms.

Lift weights.

Weight-bearing exercises increase bone density and reduce osteoporosis risk.

Starting a weight-training program at any age does the trick—studies show positive effects for postmenopausal women in particular.

Source: Mayo Foundation for Medical Education and Research,