Be Healthy in Your 20s, 30s, and 40s

Make a mental list of your three biggest health worries. Odds are they're very different from those of your little sister or older aunt. That's because, depending on where you are in life, your concerns understandably shift. "A 20-year-old isn't going to be thinking about breast cancer and heart disease the way a 40-something woman is. She's going to be more focused on, say, her sexual health," explains JoAnn E. Manson, MD, chief of the division of preventive medicine at Boston's Brigham and Women's Hospital. And rightly so, since your actual risk for certain problems also changes with age. Here, a guide to the issues you should hone in on now — and expert advice for safeguarding your health through the years.

1. Sexually transmitted diseases. A whopping 19 million new STD infections occur each year, according to the Centers for Disease Control and Prevention (CDC) — and nearly half of them are in those age 24 and under. "STDs like herpes and human papillomavirus (HPV) are rampant these days," says Steven R. Goldstein, MD, a professor of obstetrics and gynecology at New York University Medical Center. You may be in a monogamous relationship, but that doesn't make you immune. "Some STDs, such as chlamydia and HPV, are asymptomatic, which means you may have one and not know it," adds Dr. Goldstein. Left untreated, chlamydia can lead to pelvic inflammatory disease (a serious infection of the upper genital tract) and infertility. Certain strains of HPV can cause cervical cancer, although the virus often clears up on its own without incident.
2. Skin cancer. "Melanoma is the leading cause of cancer death among 25- to 29-year-old women," says Elizabeth K. Hale, MD, an assistant professor of dermatology at New York University. About 900,000 twenty-somethings are diagnosed with melanoma (the most serious type of skin cancer) each year, in part, she says, because young women don't safeguard themselves as well as their older counterparts do. Plus, many women believe that by the time they're in their 20s, the harm has already been done. "But only 75 percent of sun damage occurs by age 18, which means there's still 25 percent under your control," says Dr. Hale. Any new moles — or changes in the appearance of existing ones — should be checked out by a dermatologist.
3. Bone health. "A woman's peak bone mass is reached by the time she's in her very early 20s," says Felicia Cosman, MD, clinical director of the National Osteoporosis Foundation. "We used to believe it was much later — in your mid 30s." Maintaining that peak level is crucial, because the more bone mass you have going into the next several decades, when it rapidly declines, the lower your risk for osteoporosis will be.

1. Depression and stress. According to the National Institute of Mental Health, the median age of onset of depression is 32. The pressure-cooker lifestyle of this time is a major contributor, says Dr. Manson. Marriage, a kid or two, and a career that's in full swing add up to lots of obligations and through-the-roof stress.
2. Premenstrual syndrome. "This is a peak time for PMS," says Christiane Northrup, MD, an ob-gyn and author of Mother-Daughter Wisdom (Bantam). "In your 20s, your body is more resilient, so you have an easier time clearing excess alcohol and caffeine from your system and getting by on too little sleep — all things that are known to exacerbate PMS. But that changes in your 30s, and your body starts to say, 'Hey, keep it up and you're going to hear from me!'"
3. Overweight and obesity. Maintaining a healthy weight is crucial at any age, but now is the time when, experts say, the scale needle really starts to climb (33 percent of women in their 30s are overweight, versus 23 percent of those in their 20s). Why? Research shows that most women never lose all of the baby weight they gained — keeping on up to 8 pounds, on average, two-and-a-half years after delivery. Plus, in your early 30s your metabolism (the rate at which your body burns calories) begins to slow. Lack of shut-eye (due to those 1,001 daily to-dos) can also cause you to gain weight. A University of Chicago study found that sleep deprivation alters levels of the hormones in the body that regulate hunger, causing an increase in appetite.

1. Perimenopause. This refers to the 6 to 13 years leading up to menopause — and most women notice the symptoms in their early to mid 40s. "During that time, your metabolism slows even more, and levels of estrogen and progesterone begin to fluctuate," says Dr. Goldstein. This can lead to changes in your cycle, as well as to symptoms like irritability, memory changes, and sleep problems.
2. Heart disease. Your odds of getting this condition don't peak for a decade or so, but now is the time to take preventive action. "More than half of women over age 45 have high blood pressure, which increases your cardiovascular disease risk." says Nieca Goldberg, MD, chief of women's cardiac care at Lenox Hill Hospital, in New York City. What's more, "as your estrogen levels naturally decline, your cholesterol tends to go up and you become more prone to hypertension."
3. Type 2 diabetes. Your risk for this health problem increases now as well. According to the CDC, 1.7 percent of Americans age 20 to 39 have the disease. Between the age of 40 and 59, that number jumps to 6.6 percent. Often called "adult onset" diabetes, it can result from being overweight, having poor diet and exercise habits, or having high blood pressure and cholesterol.
4. Breast cancer. Women in their 40s account for about 18 percent of all breast cancer diagnoses; 77 percent, by comparison, occur in those over 50. So while your risk isn't enormous, it's there, says Dr. Manson — particularly if you have a family history, are overweight, or have a poor diet.

Freelance writer Shaun Dreisbach is based in Essex, Vermont, and has two children.

Originally published in American Baby magazine, February 2007.