While osteoporosis is most common in older people, it sometimes affects young people, including premenopausal women in their 20s, 30s and 40s. The term “premenopausal” refers to women who are still having regular menstrual periods and have not yet reached menopause.

Low Bone Density and Osteoporosis in Young Adult Women

While osteoporosis is most common in older people, it sometimes affects young people, including premenopausal women in their 20s, 30s and 40s. The term “premenopausal” refers to women who are still having regular menstrual periods and have not yet reached menopause. While it is uncommon for premenopausal women to have osteoporosis, some young women have low bone density which increases their chance of getting osteoporosis later in life.

One of the most common causes of low bone density in premenopausal women is low peak bone mass. When premenopausal women have osteoporosis, it may be due to an underlying medical condition or a medicine that causes bone loss. Osteoporosis that is caused by a medical condition or a medicine is called secondary osteoporosis. Sometimes premenopausal women have osteoporosis for no known reason. This is called idiopathic osteoporosis. The term “idiopathic” just means that the osteoporosis is unexplained and we cannot find a cause for it.

What Is Peak Bone Mass?

Throughout your life, you are constantly breaking down old bone and replacing it with new bone. Children and teenagers make new bone faster than they lose old bone. Even after

they stop growing taller, young people continue to make more bone than they lose. Their bones increase in density until they reach what experts call peak bone mass. Peak bone mass is the point when you have the greatest amount of bone you will ever have. Peak bone mass usually happens between the ages of 18 and 25. By age 18, bone density is nearly complete. Young adults may continue to gain a small amount of additional bone until about age 25.

Having higher peak bone mass means that you are less likely to break a bone or to get osteoporosis later in life. On the other hand, having lower peak bone mass increases your chance of getting osteoporosis. This is because women with low peak bone mass have low bone density. All women lose bone density after menopause and later in life. For women who start with lower peak bone mass, this age-related bone loss is more likely to lead to osteoporosis.

Some common reasons for low peak bone mass are listed below. These are also called risk factors. Keep in mind that many of the risk factors for low peak bone mass are also risk factors for osteoporosis.

Some Common Reasons for Low Peak Bone Mass

Being female. Women are more likely to have low peak bone mass than men.

Race/Ethnicity. Caucasian and Asian women are more likely to have lower peak bone mass than African American women.

Family history. Knowing your family history is important. If either of your parents had osteoporosis, you are more likely to have lower peak bone mass.

Poor nutrition. Eating a well-balanced diet that contains enough calcium is important for people of all ages, especially children, teenagers and young adults. To absorb calcium, the body also needs vitamin D. Girls and young women who do not get enough calcium and vitamin D may have low peak bone mass.

Low body weight. Being underweight or too thin can be harmful to bones in girls and young women. Girls and young women who diet too much are also at risk for low peak bone mass. Girls and young woman should aim for a normal healthy weight.

Infrequent menstrual periods/Low estrogen levels. Estrogen is a hormone that helps protect bones. Teenage girls and young women who often have missed periods may have low estrogen levels. Eating disorders like anorexia lead to low body weight and can cause missed periods due to low estrogen levels. Eating too little and exercising too much can also cause low estrogen levels. This sometimes occurs in runners, ballet dancers and gymnasts. Teenage girls and young women who do not have regular periods usually build less bone, and their bones are not as strong.

Not getting enough physical activity. Weight-bearing and muscle-strengthening exercises can help girls and young women have strong and healthy bones. Examples of weight-bearing exercises are dancing, jogging, using elliptical training machines and brisk walking. Examples of muscle-strengthening exercises are lifting weights, using elastic exercise bands and using weight machines. The U.S. Department of Health and Human Services (HHS) recommends that children and teens exercise for about one hour each day. Adults should aim for at least 2½ hours of exercise each week.

Smoking and drinking alcohol. Smoking is bad for your bones. In girls and teenagers, drinking alcohol is harmful to bones and can lead to bones that aren’t strong. In adults, drinking three or more alcoholic drinks a day is also harmful to bones.

Having certain medical conditions. Girls and young women who have certain medical conditions are also at risk for having either low peak bone mass or bone loss. Some of these conditions include certain digestive disorders, hyperthyroidism and depression.

Taking certain medicines. Girls and young women who take certain medicines that can cause bone loss are at risk of having low peak bone mass or bone loss. One example is steroid medicines, such as prednisone and cortisone, which are used to treat conditions like asthma.

Depo-Provera® and Oral Contraceptives

Depo-Provera®. Research studies suggest that women taking Depo-Provera® may lose bone density. For teen girls and young women, it is not known if Depo-Provera® reduces peak bone mass or increases the risk of osteoporosis and broken bones later in life. While bone density appears to recover after a person stops taking Depo-Provera®, it may take a long period of time. Because of concerns about its effect on bones, the U.S. Food and Drug Administration (FDA) has issued a warning advising that Depo-Provera® should not be used for more than two years when other forms of birth control are available and suitable. Oral contraceptives. At this time, research does not show that oral contraceptives are harmful to bones. However, more studies are needed before we can know for sure.

Diagnosing Osteoporosis in Young Women

Diagnosing osteoporosis in young women usually involves several steps. While these steps

may differ for each person, they may include:

• Your medical history
• Physical exam
• Bone mineral density (Bone density) testing
• Lab tests
• X-rays

Medical history. Your healthcare provider may ask you questions about your medical history.

Here are some questions he or she may ask you:

• Have you ever broken a bone as an adult?
• Did your mother or father have osteoporosis? Did either of them ever break a bone as an adult?
• Have you, your parents or siblings ever had kidney stones?
• Have your periods always been regular?
• Do you have any problems eating or digesting food?
• Do you currently take any medicines? Have you taken any medicines in the past?
• Have you ever been diagnosed with any medical conditions or health problems?
• Do you eat foods that contain calcium, like milk, yogurt or cheese? Do you take any dietary supplements?
• How often do you exercise and what kinds of exercises do you do?
• Have you ever smoked?
• Do you drink alcohol?

Physical exam. Your healthcare provider may check for certain risk factors or signs of osteoporosis by:

• Measuring your height and weight
• Calculating your body mass index (BMI)
• Examining your spine

Bone density testing. A bone density test uses a special machine to measure bone density in postmenopausal women and men age 50 and older. This test lets a person know the amount of bone they have in the hip, spine or other bones. It is how osteoporosis is diagnosed in older people. This test should be done on a DXA machine. DXA stands for dual energy x-ray absorptiometry.

Diagnosing osteoporosis in premenopausal women is not straightforward and can be quite complicated. First of all, bone density tests are not routinely recommended for young women. Here are some reasons why:

• Most premenopausal women with low bone density do not have an increased risk of breaking a bone in the near future. Therefore, having information about their bone density may only cause unnecessary worry and expense.
• Some premenopausal women have low bone density because their genes (family history) caused them to have low peak bone mass. Nothing can or should be done to change this.
• DXA tests can underestimate bone density in women who are small and thin. Therefore, a DXA test may indicate that a small person has low bone density, but the bone density is actually normal for the person’s body size
• Osteoporosis medicines are not approved or advised for most premenopausal women. Bone density tests are used to help guide decisions about treatment.

Bone density tests are usually only done for premenopausal women if they break several bones easily or break bones that are unusual for their age, such as bones in the hip or spine. Also, if you have a condition or take a medicine that causes secondary osteoporosis, your healthcare provider may order a Bone density test. Your healthcare provider may also recommend a bone density test if he or she is concerned about your bone health for other reasons.

Understanding your bone density test results. A bone density test result shows a Z-score and a T-score. If your healthcare provider recommends that you have a bone density test, he or she will look at your Z-score and other information about your health to decide if you have osteoporosis or another bone problem. A Z-score compares your bone density to what is normal for someone your age. While a Z-score alone is not used to diagnose osteoporosis in premenopausal women, it can provide important information. Here are some tips to help you understand your Z-score:

• If your Z-score is above -2.0, your bone density is considered within the ranges expected for your age or normal according to the International Society for Clinical Densitometry (ISCD). For example, a Z-score of +0.5, -0.5 and -1.5 is considered normal for most premenopausal women.
• If your Z-score is -2.0 or lower, your bone density is considered below the expected range. Examples are -2.1, -2.3 and -2.5. If your Z-score is in this range, your healthcare provider will consider your health history and possible causes of bone loss, including secondary osteoporosis, before making a diagnosis of osteoporosis.
• If your Z-score is normal, but you’ve broken one or more bones from a minor injury, your healthcare provider may diagnose you with osteoporosis because some people with normal bone density break bones easily. As mentioned above, a bone density test will also show a T-score. A T-score compares bone density to what is normal in a healthy 30-year-old adult.

T-scores are used to diagnose osteoporosis in postmenopausal women and men age 50 and older, but not in premenopausal women.

Repeating Your bone density Test. A second bone density test one or two years later will tell if a person has low peak bone mass that is staying the same or if a person is losing bone. If a person’s bone density drops a lot between the first and second test, this suggests that the person is losing bone and requires further evaluation by a healthcare provider.

Lab Tests You May Need. If you have low bone density or osteoporosis, your healthcare provider may do one or more lab tests to find out what is happening in your body. Certain lab tests, which are not recommended for everyone, can help you to:

• Know if you are getting enough vitamin D
• Find out if you have a condition that can cause bone loss
• Learn if you’re losing bone faster than normal

X-Rays. An x-ray is the most common way to tell if you have a broken bone. Sometimes there is no pain with broken bones in the spine. Your healthcare provider may order an x-ray of your spine if he or she suspects that you could have broken a bone, especially when you:

• Have lost height
• Have stooped or hunched posture
• Develop back pain

Treating Osteoporosis in Young Women

Most of the osteoporosis medicines available at this time are not approved by the FDA for use in premenopausal women. But, for women who have taken steroid medicines for a long time, three osteoporosis medicines are approved for the prevention and treatment of osteoporosis. In very rare cases, a healthcare provider may recommend that a premenopausal woman consider taking an osteoporosis medicine for other reasons. Examples include when a woman breaks a bone because of low bone density or has severe bone loss due to a medical condition.

Conclusion

You are never too young or old to take care of your bones. Make sure you are getting the recommended amounts of calcium and vitamin D every day. It’s also important to eat plenty of fruits and vegetables, exercise regularly and avoid having too much caffeine, cola drinks and sodium (salt). Don’t smoke or drink too much alcohol. These lifestyle habits can help you protect your bones and decrease your chance of getting osteoporosis. If your healthcare provider hasn’t talked to you about your bone health, it’s time for you to bring it up!

Additional Related Topics

Having a BMD Test - information about bone density testing, and understanding what your results mean.

Medicines That May Cause Bone Loss - more information about medicines and their relation to bone loss

Diseases and Conditions that May Cause Bone Loss - information about medical conditions that may bone loss.