Bones are high up on the list of things we take for granted -- until they fail us. Having weak bones, a condition doctors call low bone mass, makes you vulnerable to fracture -- and not just, say, a broken arm. Bone fractures that result from osteoporosis are often in the hips or spine, and they can incapacitate you for months. Even worse, fractures can trigger what experts call a "cascade" of health symptoms, ending in lifelong disability or even death.
While osteoporosis might sound like an older person's disease, it's actually the end product of a long, gradual process that affects every adult from the teenage years on. Believe it or not, we stop building bone when we're between 20 and 25 years old, a point at which we reach what's called "peak bone mass." We start losing bone sometime between 30 and 40, depending on how vigilant we are about diet, exercise, and other factors that keep our bones strong.
How do you know if your bones will hold you up for many years to come? Test yourself by using this list of 12 common risk factors for osteoporosis. If you meet two or more of these criteria, talk to your doctor about whether you should have a bone density scan.
1. Have you ever suffered from an eating disorder?
A history of anorexia is one of the biggest red flags for osteoporosis, says Columbia University endocrinologist Elizabeth Shane, who studies osteopenia -- the early stage of osteoporosis -- in younger women. That's because when a woman's body weight drops too low, it lowers hormone levels, and she typically starts skipping periods. "Anything that lowers estrogen levels interferes with bone building," Shane says.
2. Do you have a first- or second-degree relative who developed osteoporosis before the age of 50 or before menopause?
Family history is a major risk factor for poor bone health. If you come from a family where the older adults have histories of fractures, poor posture, loss of height, or similar problems, bring this to your doctor's attention.
3. Do you smoke?
Statistically, smoking has a high correlation with osteoporosis, though experts have not yet pinned down the exact process by which smoking sabotages bones. "Smoking is one of the worst lifestyle factors for brittle bones," says Robert Recker, a physician and director of the osteoporosis research center at Creighton University in Nebraska.
4. Do you drink more than two alcoholic drinks a day (three if you're a man)?
Alcohol is a bone-weakener; it leaches calcium, magnesium, and other minerals out of your bones. The more you drink, the more likely that it's happening. Women are more vulnerable to this type of bone loss than men, perhaps because they're more vulnerable to the effects of alcohol in general.
5. Have you had one or more fractures, particularly fractures that seem worse than you'd expect from the cause?
One of the most common ways people find out they have osteoporosis is when a minor fall leads to an injury that's more serious than you'd expect. Your bones need to be strong enough to sustain some impact, and if they aren't, you want to know about it. Osteoporosis experts suggest that any adult who's had more than one fracture, or a fracture that seemed surprisingly severe, should ask about having a bone density test.
More risk factors for osteoporosis
6. Do you take prednisone or other corticosteroids, antidepressants, or a thyroid hormone?
Taking cortisone drugs over a long period of time saps calcium, vitamin D, and other nutrients from your bones and interferes with hormone levels, leaving your bones prone to bone loss. This is particularly the case for women, who are more likely to get autoimmune diseases, because normal estrogen levels are necessary for maintaining healthy bone. The group of antidepressants called SSRIs has also been associated with a higher incidence of osteoporosis. Taking thyroid hormone for an underactive thyroid can cause bone loss as well.
7. Do you have Crohn's disease, lupus, rheumatoid arthritis, or another autoimmune condition?
Experts know from numerous studies that people who have autoimmune diseases have osteoporosis at a much higher rate than the average. This is primarily due to the medications -- typically corticosteroids -- used to treat these conditions.
8. Are you over 50?
Age itself is a risk factor for osteoporosis, since our bones lose strength with age. Osteoporosis is much more common in men older than 50 and in women who've been through menopause. In fact, a man over 50 is more likely to break a bone from osteoporosis than he is to get prostate cancer. However, because of changes in diet and lifestyle, osteoporosis and its precursor, osteopenia, are more and more common among people in their thirties and forties.
9. Are you a woman?
Women are at increased risk of osteoporosis, partly because they tend to have smaller frames to begin with, and partly because the hormonal changes women go through contribute to bone loss. According to the National Osteoporosis Foundation, 80 percent of the 10 million Americans with osteoporosis are women.
10. If you're a woman, are your periods irregular or infrequent?
Missed periods are usually caused by low levels of the hormone estrogen, and low estrogen contributes directly to bone loss. There are many reasons women have low estrogen; overexercising, eating disorders, and polycystic ovary disease are some of the most common. Whatever the cause, be sure to talk to your doctor, since your bone strength can be compromised.
11. Are you thin or small-framed?
This one's a matter of basic logic: If your bones are small to begin with, you have less to lose and need to be particularly vigilant. That doesn't mean that heavy or big-boned people don't get osteoporosis -- just that people who are thin or small-boned don't have as far to go before they're at risk for fracture.
12. Do you drink milk?
The simple dietary choices we make, like whether we have a glass of milk or a soda with lunch, have a much bigger effect on bone health than most people realize, says osteoporosis specialist Robert Recker. It's not just the calcium content in milk that makes it so important; it's the vitamin D. Most American adults are severely D-deficient, Recker says, putting us at risk not only for weak bones but for several types of cancer. And milk, which is fortified with vitamin D, is one of the only dietary sources of this important nutrient.