What is the Difference Between Bone Mass and Bone Density?

Bone mass and bone density are related but distinct concepts in the context of bone health. Here are the key differences between the two:

• Bone Mass: Bone mass refers to the amount of bone tissue in an individual's body, which is determined largely by genetics. It is a function of bone size and volumetric bone mineral density (BMD). A person with low bone mass has low bone density, and vice versa.
• Bone Density: Bone density, also known as bone mineral density (BMD), is the amount of bone mineral in an individual's bones. It is a key determinant of bone strength. A bone density test, also known as a bone mass measurement or bone mineral density test, measures the strength and density of bones.

In summary, bone mass is the total amount of bone tissue in a person's body, while bone density is a measure of the amount of bone mineral within the bones. Both are important factors in assessing bone health and determining the risk of fractures or other bone-related issues.

Comparative Table: Bone Mass vs Bone Density

Bone mass and bone density are related but distinct concepts in understanding bone health. Here is a table highlighting the differences between the two:

Bone mass refers to the total amount of bone tissue in the body, which is made up of both cortical (outer shell) and trabecular (spongy inner layer) bone. Bone density, on the other hand, refers to the amount of bone mineral per unit area or volume of bone tissue. Bone density testing is typically performed using dual X-ray absorptiometry (DXA) or, in some cases, high-resolution computed tomography (CT).

While bone mass and bone density are interconnected, they are affected by different factors. Bone mass is influenced by genetic, lifestyle, and nutritional factors, while bone density is often assessed to determine if a person has low bone density (osteopenia) or osteoporosis. A bone density (BMD) test score, known as the T-score, compares a person's bone density to the bone density of an average healthy 30-year-old adult. A T-score of 0 indicates that the person's bone density does not deviate from the average, while positive or negative values indicate that the bone density is above or below the average, respectively.