What Is Osteoporosis?

Osteoporosis is a condition involving bones that are brittle and can break from minor falls and everyday activities like bending or lifting light objects. It is the most prevalent bone disease, affecting around 10 million people in the United States.

The most common type of fracture associated with osteoporosis occurs in the vertebrae, which are the bones in the spine. These are known as compression fractures, which can affect one or more vertebrae. Fractures also frequently occur in the bones of the wrist or hip.

There are different reasons why osteoporosis can occur. The two main types of osteoporosis are determined based on the cause of weakening bones:

  • Primary osteoporosis: Primary osteoporosis generally occurs with aging and is the most common kind of osteoporosis. For bones to stay strong, the body has to consistently generate new bone, replacing older bone in a process called remodeling. As a person gets older, production of new bone slows, which is typically related to reduced levels of certain hormones as well as changes in vitamins and nutrients in the body.
  • Secondary osteoporosis: Secondary osteoporosis occurs when another health condition or medication causes a weakening of the bones. For example, this can occur with diseases or drugs that disrupt hormone levels or affect the absorption and function of vitamins and nutrients.

Rarely, younger adults or children can develop osteoporosis without any clear cause. This is known as idiopathic osteoporosis.

People with any type of osteoporosis often do not have any apparent symptoms, which is why osteoporosis is called a “silent” disease. It is normal for people to not know that they have osteoporosis until they already have a broken bone.

Pain can be a symptom of osteoporosis after a fracture has occurred. However, many vertebral fractures do not cause pain or other early symptoms and may only be detected when a person has testing done for other health issues.

Broken bones can be a serious health complication for people with osteoporosis. Injuries from falls are often worse in people with this condition. Fractures of the hip, spine, and other bones can cause significant pain and may result in disability, especially in older adults.

The Role of Osteoporosis Tests

Osteoporosis tests can be recommended for a number of different purposes. Testing is generally used for screening, diagnosis, risk assessment, or monitoring.

Screening is looking for signs of a health condition in someone who does not have any symptoms. The goal of screening is to detect weakened bones in people who do not have pain or other signs of osteoporosis. Identifying fragile bones may help prevent future fractures.

Diagnosis is testing done to determine the cause of a person’s symptoms. Tests can check for osteoporosis after a bone fracture has been detected. Diagnostic tests can also help distinguish between osteoporosis and other health conditions that can affect the bones.

Risk assessment is a way of predicting how likely a person is to experience a health problem. People with osteoporosis can have different degrees of bone weakness, and testing can identify who may be at a higher risk of fractures. Specific formulas have been developed to help doctors estimate an individual’s likelihood of breaking a bone.

Monitoring is assessing how a disease responds to treatment or how a person’s condition changes over time. For people with osteoporosis, periodic testing can help track their risk of fracture and determine if treatment is working.

Many tests can be used for more than one purpose, so it is important for a patient to talk with their doctor about the type of osteoporosis testing that is recommended and its specific role in their health care.

Who should get testing?

There are many situations in which osteoporosis testing is appropriate. Determining who should get testing is based on a patient’s specific situation and whether testing is being used for screening, diagnosis, risk assessment, or monitoring.

Screening

Screening tests look for signs of bone weakness in people who do not have any symptoms of osteoporosis. Screening for osteoporosis is typically done in people who have a higher risk of developing the condition.

Osteoporosis is more common in older adults. It occurs more frequently in women, and this risk increases after menopause when changes to hormone levels can reduce bone strength.

As a result, screening for osteoporosis is typically recommended in women that are postmenopausal and over the age of 65. Screening may be recommended for postmenopausal people under 65 if they have an elevated risk of osteoporosis. Factors that can increase the risk of developing osteoporosis include:

  • Having a parent who experienced a hip fracture
  • Excess alcohol consumption
  • Cigarette smoking
  • Low body weight

There is no widespread consensus about screening for osteoporosis in men. Some experts recommend screening in anyone over age 70, but other experts only conduct testing in older men if they have risk factors for osteoporosis.

Screening may be recommended in transgender people beginning at age 65, regardless of their sex assigned at birth. Screening may be initiated earlier depending on an individual’s risk factors for osteoporosis, including any medical history of gender-affirming medical treatments.

Screening for osteoporosis may also be considered in people who have health conditions or take medications that can lead to a weakening of the bones. For example, screening may be advised for people with inflammatory bowel disease, HIV, and some kidney diseases as well as people who take certain types of steroid medications.

Any person with concerns about their risk for osteoporosis should speak with their health care provider who can address the benefits and downsides of screening in their situation.

Diagnosis

Testing to diagnose osteoporosis is often performed if a person has signs or symptoms of fragile bones.

Osteoporosis may not cause any symptoms until a fracture occurs. Even then, many people will have a fracture, such as a vertebral compression fracture, without any immediate symptoms. In some cases, a fracture that doesn’t cause any symptoms may be seen on an imaging test for another health issue.

When symptoms occur, pain can be an initial sign of a fracture. Pain may come on sharply or develop gradually over time. Vertebral fractures may cause other symptoms such as a stooping posture and a loss of height.

Fractures that occur from low-impact falls or everyday activities, known as fragility fractures, occur much more often in people with osteoporosis. People with these kinds of bone fractures may be referred by their doctor for testing to check for signs of bone weakness and osteoporosis.

Risk assessment

Testing to assess a person’s risk of bone fractures is common in anyone who has been diagnosed with osteoporosis through initial screening tests or after having signs or symptoms of the condition. This risk assessment allows the doctor to consider various factors that influence how likely a patient is to break a bone in the future.

Monitoring

People who have osteoporosis may have monitoring tests performed periodically to see whether their bones are still fragile and whether treatment is helping to reduce their risk of fractures. The frequency of this testing can depend on the cause and severity of bone weakness. Some people may have repeat testing every few years, while others may go 10 years or more between monitoring tests.

Getting test results

Results from osteoporosis tests are usually provided by your doctor or another health care provider. Some test results are available rapidly, but others may take several days. The results may be explained to you during an in-person appointment or over the phone. Detailed test reports may be available through an online health portal or by mail.

Depending on the type of tests that you take, your doctor may tell you whether you have osteoporosis. Testing may also reveal osteopenia, which is a less severe form of bone weakness that can become osteoporosis over time.

Your doctor may share your personal bone density score or use a formula that estimates your risk of bone fractures. They can consider multiple factors that affect bone health when evaluating your specific situation and deciding whether to recommend treatment.

For any tests that you take, ask your doctor about when you can expect the results, what may be learned from testing, and how the results will be communicated to you once they are available.

Types of Osteoporosis Tests

There are several different kinds of tests and examinations for osteoporosis. For almost all patients, a physical exam and health review are important parts of assessing bone health. A range of additional tests may be considered based on your individual circumstances.

The following sections provide more information about the various types of tests and evaluations related to osteoporosis.

Health history

A health history involves your doctor asking various questions about your health status. This includes a discussion of your current symptoms as well as your past medical experiences and family history of different health issues.

During this health review, you may be asked about prior bone fractures, other health conditions you have, the medications you take, your lifestyle habits, whether you’ve been through menopause, and/or whether any family members have had osteoporosis.

In addition, the doctor may ask about any health changes, including symptoms that could be associated with bone fractures. If you have recently had a bone fracture, the doctor will ask what caused it. If you had a fragility fracture, the health review itself may be sufficient to diagnose osteoporosis.

Physical exam

A physical exam allows your doctor to check for any signs of an underlying health problem. This can include looking closely at any areas where you may be experiencing pain.

A physical exam for osteoporosis may involve checking your posture, measuring your height and weight, assessing your muscle strength, and analyzing how you walk.

Abnormal findings on a physical exam can provide evidence of bone weakness or another health condition. These findings can help your doctor determine whether additional testing for osteoporosis is necessary.

Central DXA scan

Dual-energy x-ray absorptiometry (DXA or DEXA) is a type of test that measures bone density, also known as bone mineral density (BMD). A central DXA scan evaluates bone density in areas that are prone to fracture. In most cases, a central DXA measures bone density in the spine and hip.

A central DXA scan is both the most accurate and most common type of bone density test. It uses a low-dose x-ray to determine the amount of minerals in a specific area of bone.

By examining the bones in at least two sites, a central DXA test can provide specific bone density scores:

  • A T-score compares your bone density to a healthy young adult.
  • A Z-score compares your bone density to an average person of your age.

Central DXA scans play an important role in osteoporosis testing. They are frequently used to screen for bone weakness and to diagnose osteoporosis. T- or Z-scores can enable risk assessment for fractures, and periodic central DXA scans allow doctors to monitor changes in bone density over time and in response to treatment.

Different machines for DXA scanning have their own calculation methods, so scores from one device may not be comparable to scores from others. If multiple central DXA tests are performed over time, they are done on the same machine or on machines that have been calibrated to account for this difference.

Vertebral fracture assessment

A vertebral fracture assessment (VFA) is a type of test that is often performed at the same time as a central DXA scan. During a VFA, very low-dose x-rays are used to check the spine for signs of a fracture or other abnormality. This can help identify vertebral compression fractures and evaluate the risk of future fractures.

Peripheral DXA scan

A peripheral DXA scan measures bone density in the heel, fingers, or wrist rather than in the spine or hip. Peripheral DXA machines are small and portable, so this type of testing may be available at some health fairs or pharmacies.

While a peripheral DXA scan is usually more convenient than a central DXA scan, it does not predict fracture risk as accurately and cannot be used to diagnose osteoporosis. For this reason, abnormal results on a peripheral DXA scan typically must be confirmed with a central DXA scan.

Other bone fragility tests

While DXA scans are the most common ways of evaluating bone health, other tests may be used when DXA scanning is not possible or available. Examples of other bone fragility tests include:

  • Quantitative ultrasound (QUS): This test uses ultrasound to create an image of a bone, usually around the heel. This can help predict the risk of fractures, but it does not measure bone mineral density. While a QUS device is portable and can provide helpful information, this test cannot be used alone to diagnose osteoporosis or monitor response to treatment.
  • Quantitative computerized tomography (QCT): This type of test uses computerized tomography (CT) scanning to measure the spine’s bone density. QCT scans rely on multiple x-ray pictures that a computer combines into a multidimensional image. Quantitative CT scanning can correctly measure bone density, but, compared to DXA scans, it involves more radiation exposure and is less frequently used.

Other imaging tests

Osteoporosis testing can include other tests that provide an image of the bones. These tests can detect fractures that may be tied to osteoporosis. Examples of imaging tests include:

  • X-rays: An x-ray can rapidly create an image of one or more bones. Doctors may order an x-ray of different parts of the body such as the hip, part or all of the spine, or the bones in the chest and the spine.
  • Magnetic resonance imaging (MRI): An MRI uses powerful magnets to generate pictures of the inside of the body. MRI can be used for different parts of the body to look for signs of damage. For example, an MRI of the lumbar region may find fractures of the lower spine associated with osteoporosis.

Laboratory tests

After a diagnosis of osteoporosis, a doctor may recommend certain laboratory tests in order to check for underlying health conditions that could be affecting the bones.

This testing often involves a blood sample collection. Several different substances can be measured in the blood to look for abnormalities that could be a sign of other health problems, including diseases that affect the kidneys.

There are several kinds of blood tests that may be performed in people with osteoporosis or low bone density. Some of these tests examine levels of different vitamins and minerals such as:

Testing may also measure substances in the blood that can indicate how well organs like the liver and kidneys are working. These tests include:

Many of these measurements are included in a multi-component test like a comprehensive metabolic panel (CMP). In addition, the following laboratory tests may be ordered to check for abnormalities in blood cells and specific hormones levels:

In some cases, urine tests may also be recommended to look for underlying conditions. The exact types of laboratory tests that are prescribed will depend on a patient’s symptoms and health history.

Bone turnover marker tests

Bone turnover marker (BTM) tests try to determine how quickly bone is being broken down and reformed. These tests are not widely used in osteoporosis testing, but they may be recommended in certain situations. For example, BTM tests may help distinguish osteoporosis caused by normal aging from bone loss related to kidney diseases. Further research is necessary to further clarify and expand the role of bone turnover marker tests in people with osteoporosis.

Bone biopsy

A bone biopsy is an operation to remove a small piece of bone that can be looked at under a microscope or tested for abnormalities.

Bone biopsies are rarely needed for osteoporosis testing, but they may be necessary in some cases. For example, a bone biopsy may be required to determine if bone damage is being caused by a kidney disease or by osteoporosis.

Getting Tested for Osteoporosis

Osteoporosis tests are ordered by a health care provider. Testing is usually performed in a medical setting like a health clinic, doctor’s office, outpatient medical center, or hospital.

At-home testing

No at-home tests are available that can detect osteoporosis. Only a health care provider can diagnose osteoporosis, and testing must be performed by trained health professionals.

Some at-home blood tests may measure vitamins, nutrients, or hormones that can be related to how the body builds and maintains bone mass. However, levels of these substances in the blood alone cannot determine the strength of bones or whether someone has osteoporosis.

It is important for anyone concerned about the health of their bones to talk with their doctor about the most appropriate type of testing for their situation.

Comparing Tests

Osteoporosis testing in children vs. adults

While osteoporosis is much more common in older adults, it can also occur in young people. In some young adults and children, a rare type of osteoporosis develops without any identifiable cause, which is known as idiopathic juvenile osteoporosis.

Many of the same tests for osteoporosis in adults are also used for children, but the test results must be interpreted carefully to account for the fact that children’s bones are not fully developed. As a result, doctors use different criteria to diagnose osteoporosis in children than in adults.

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