A blood test can help detect whether a person has an underlying condition that could cause bone loss. However, it cannot show a person has osteoporosis by itself.
Blood tests can provide information about a person’s overall health and whether an underlying condition may be present. If the results come back with irregular findings, a doctor may order additional tests to determine the cause.
This article reviews how doctors use blood tests in diagnosing osteoporosis, what they can show, what to expect, and more.
Blood tests can help during the diagnosis of osteoporosis, but a blood test cannot show that a person has the condition.
Instead, diagnosis of osteoporosis often involves:
- a review of personal and family medical history
- a physical examination
- a bone density test, such as a dual-energy X-ray absorptiometry (DEXA) scan
- blood and urine testing
- using the Fracture Risk Assessment Tool to determine a person’s FRAX score
A doctor can combine the results from the different tests and assessments to ascertain if a person has osteoporosis. Some of the tests — including blood tests — may help establish if a person has an underlying condition contributing to low bone density.
Learn more about how doctors diagnose osteoporosis.
Blood tests are often a part of the testing involved in diagnosing osteoporosis. When a doctor orders a blood test, they are looking for underlying conditions that may be causing a person’s bone loss. They may also request a urine test for the same purpose.
A doctor will likely order a standard blood panel. This panel may include:
- complete blood count (CBC)
- liver function tests
- chemistry levels (calcium, renal function, magnesium, and phosphorus)
- serum 25(OH)D level
- thyroid-stimulating hormone (TSH) level
- parathyroid hormone (PTH)
- total testosterone and gonadotropin levels in younger people assigned male at birth
They may also request additional blood tests if they suspect certain conditions or issues may be present. They may also look for:
- tissue transglutaminase antibodies
- serum protein electrophoresis (SPEP)
- serum immunofixation
- serum free light chains
- iron and ferritin levels
- bone-specific alkaline phosphatase
A person’s doctor will be able to explain the tests they order and what the results may indicate.
A blood test for osteoporosis will require a person to have a small amount of blood drawn.
Some healthcare facilities, such as hospitals, may be able to draw blood onsite. Primary care or other doctors may require a person to visit a specific lab. In either case, a doctor or other medical professional will need to order the specific blood test or tests they require.
The process usually takes a few minutes and typically involves the following steps:
- The technician will likely prepare the arm with an alcohol wipe and look for a suitable vein to draw the blood.
- They will then insert a needle and take the required amount of blood. A person may feel a pinch or sting from a needle, and there may be a small amount of blood coming from the insertion point.
- The blood sample will go to a lab for analysis.
- The lab will then send the report to a doctor or may provide results to the person via an online, secure portal.
Before the test, it is best for a person to inform the doctor about any medications they take in case they need to pause them before the blood test. They may also need to fast, or not eat anything, before the procedure.
Depending on the test results, a doctor may order additional blood or other tests to help determine the cause of unusual findings.
Learn more about blood tests.
Blood tests for osteoporosis may occur if a doctor suspects a person has a condition that may cause bone loss or increase the risk of osteoporosis.
Conditions that may increase the risk of osteoporosis include:
- rheumatoid arthritis, inflammatory bowel disease, and
other autoimmune conditions
- endocrine disease
- hormonal diseases
- certain cancers
- anorexia nervosa or bulimia nervosa
- gastrointestinal conditions
It is best for a person to contact a doctor if they have concerns about the risk factors for osteoporosis.
Blood tests may help a doctor determine if an underlying condition may be causing bone loss or osteoporosis. It makes up part of a diagnostic assessment but cannot specifically show a person has osteoporosis.
Instead, a doctor will likely review medical history, perform a physical exam, and order additional testing to assess bone density and fracture risk.