Dr. Oz's Guide to Getting Healthy in Your 40s

Test This: Schedule Your First Mammogram

Over the past few years, debate has raged about whether to screen women for breast cancer at age 40 or 50. Some experts argue that a harmless spot found during a mammogram may prompt healthy 40-year-olds to undergo unneeded biopsies. Yet a study of more than one million women in Sweden found that testing at a younger age led to a 29 percent decrease in deaths. Early detection is critical if you have dense breasts or if your mother or sister has had breast cancer—factors that can significantly increase your risk of developing the disease.

Next: Dr. Oz's 24 smart strategies for feeling great at every age