Be your healthiest today: your concerns are different now than they were 10 years ago, so why follow a one-size-fits-all plan? We show you where to focus your efforts

Hit the gym, whip up a lowfat meal, meditate. Sometimes there aren't enough hours in the day to hold down a job and do everything you're supposed to do to stay in tip-top shape. Rather than try to squeeze it all in, take stock of what's most important for your health right now. "As you age and your lifestyle changes, your priorities naturally shift, and your habits should reflect that," says Brent Agin, M.D., a physician in Clearwater, Florida, and the co-author of Healthy Aging for Dummies. That's why we asked the experts to spell out the steps women in their 20s, 30s, and 40s should never miss. Follow this simple decade-to-decade guide and you'll fight disease, ward off weight gain, and feel your best for years to come.

Count your cocktails

Given those happy hours with your co-workers, dates at the wine bar, and that mimosa-filled bridesmaids' brunch, you have a drink most days of the week. No big deal, right? "Actually, it depends on your family history," says Arthur Klatsky, M.D., an adjunct investigator at Kaiser Permanente's Division of Research in Oakland, California. Research shows that a daily drink can protect your heart, but Klatsky's study found it can also increase your chances of developing breast cancer by 10 percent. Toss back three cocktails a few times a week and those odds jump to 30 percent. "Alcohol causes your body to pump out more estrogen," explains Klastsky. "Over time elevated levels can activate hormone-sensitive breast cancer tumors."

The bottom line? "If breast cancer runs in your family, it's probably best to scale back to a few drinks a week, tops," he says. But if your main concern is heart disease, a single serving of alcohol--that equates to 1.5 ounces of liquor, 5 ounces of wine, or 12 ounces of beer--a day may be well worth it.

Practice safe sun By now you've probably heard the "Wear sunscreen!" recommendation a hundred times over. Yet this message still isn't registering among 20-somethings: Melanoma is the top cause of cancer among 25-to 29-year-old women, according to the Fournal of the National Cancer Institute. In part, this is due to the fact that more than 60 percent of young adults suffer at least one sunburn per year, according to another study. So before you head outside, apply a sunscreen with SPF 30 to all exposed body parts. If you're planning on spending the day outdoors, stash a 3-or 4-ounce tube of waterproof sunscreen in your bag and use the whole thing. Every two hours, apply about an ounce, or 2 tablespoons, all over your body.

Research your family tree Everyone tells you that you got your grandmother's smile, but what they may not realize is that you might also have her propensity for high blood pressure, type 2 diabetes, osteoporosis, or Alzheimer's. "The majority of diseases and conditions have some type of hereditary factor," says Angela Trepanier, a certified genetic counselor at Wayne State University. Knowing which conditions are floating around in your gene pool can help you as well as your physician be on the lookout for problems in their earliest and most curable stages.

Speak to your relatives about any health problems they've had, such as cancer, heart disease, depression, birth defects, and alcoholism. Quiz your grandparents about their parents and siblings: If close relatives of yours have had breast cancer, for example, your risk of having the gene for that disease is higher. Then plug the information into a family history form, such as those on familyhistory .hhs.gov, and bring it to your next checkup.

Get to know your gynecologist

This year, 19 million Americans--half of them under the age of 25-will catch a sexually transmitted disease, reports the Centers for Disease Control and Prevention. "Even if you're in a monogamous relationship, it's vital that you visit your gynecologist every year," says Agin. "Some diseases have few if any symptoms, so years can go by before they're detected."

Chlamydia and gonorrhea, for example, can cause pelvic inflammatory disease, a potentially dangerous infection of the uterus, fallopian tubes, and other reproductive organs. Left unchecked, these conditions can lead to permanent damage.

"If you're not in a committed relationship, always use a condom," says Agin. That seems like a no-brainer, but one study found that less than 20 percent of single women say they use a condom every time.

Put your girlfriends on speed dial

Remember when you had time to meet up for a movie after work? Those days are long gone. But even though you have more pressing priorities of late, it's still important to catch up with pals.

"Having a strong network is essential for your overall well-being," says Agin.

Without a shoulder to lean on, he says, your stress levels can go unchecked. In the short term, this can make you snappy and irritable, but in the long run, it can raise your blood pressure and blood sugar (a risk factor for diabetes). In fact, a study in the journal Psychosomatic Medicine found that lonely women were more likely to have heart disease and twice as likely to die than those with large social circles.