Doctors do not consider osteoporosis an autoimmune condition. However, the immune system and autoimmune conditions may play a role in its development.

Osteoporosis is a bone disease that occurs when the mass and density or formation and strength of bones are low. The condition increases a person’s risk of fractures or breaks.

The immune system may play a role in bone formation, and autoimmune disorders may increase a person’s risk of developing osteoporosis. This article reviews what researchers know about the condition, including its causes, risk factors, and more.

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Osteoporosis is a bone condition, not an autoimmune condition. However, several autoimmune disorders may increase a person’s chances of developing osteoporosis.

An autoimmune disease occurs when the immune system mistakenly attacks a healthy part of the body, resulting in inflammation and damage to the organ or tissue and causing symptoms to develop.

This is not the case with osteoporosis. Instead, it develops due to decreasing bone density and strength. It may occur due to several underlying risk factors, including conditions such as:

Learn more about bone diseases.

Osteoporosis and the immune system

Although doctors do not consider osteoporosis an autoimmune condition, emerging evidence suggests the immune system and autoimmune disorders may play a role in its development.

A 2017 study noted that the immune and bone systems share similar regulatory mechanisms and molecules supporting bone growth. It found that autoantibodies may contribute to bone loss.

Autoimmune cells are proteins the immune system creates that attack healthy cells, such as those in bone. These changes in the immune system may directly affect bone density by altering bone formation.

In a 2021 study, researchers further explored how the immune system interacts with the bones. They noted that several autoimmune disorders, including rheumatoid arthritis, have a link to osteoporosis, due to inflammatory cells directly or indirectly affecting bone formation.

Learn more about how the immune system works.

The exact underlying cause of osteoporosis is unclear. However, experts have identified several risk factors that increase a person’s chances of developing the condition. These include:

  • Sex: People assigned as female at birth generally have smaller bones with less mass, increasing the risk of osteoporosis.
  • Age: Slowing bone growth can weaken bones. Osteoporosis may be more likely to occur later in life.
  • Race: White and Asian females have the highest risk of developing the condition.
  • Hormonal changes: Low levels of estrogen or testosterone can increase the risk of osteoporosis.
  • Diet: A person may be at increased risk of osteoporosis if they consume a diet low in calcium and vitamin D.
  • Body size: People with slender, thin bones have an increased risk of osteoporosis.
  • Family history: Having parents with osteoporosis may make a person more likely to develop the condition.
  • Lifestyle factors: Certain lifestyle factors, such as smoking and excess alcohol consumption, may increase the risk of osteoporosis.
  • Certain medications: Using certain medications long-term can increase the risk of osteoporosis. This includes proton pump inhibitors, antiepileptic medicines, and more.
  • Other medical conditions: Having HIV, certain cancers, GI conditions, and other medical issues can increase a person’s risk.

Learn more about osteoporosis causes and risk factors.

Autoimmune conditions and osteoporosis

Researchers are looking into how the immune system and autoimmune conditions may increase a person’s risk of developing osteoporosis.

They note that both autoantibodies and inflammation may contribute to bone formation and density changes, which can lead to osteoporosis.

This means that autoimmune conditions may increase a person’s risk of osteoporosis. However, more research is necessary.

Learn more about autoimmune conditions.

Below are answers to some commonly asked questions about osteoporosis and autoimmune conditions.

What type of disease is osteoporosis?

Osteoporosis is a bone condition. It occurs when bone mineral density and mass decrease or when the structure or quality of bone changes. It can lead to decreased bone strength and an increased risk of fractures.

Is any bone disease an autoimmune condition?

Autoimmune conditions and bone diseases are separate. However, autoimmune conditions can cause secondary bone disease. Examples that can affect bone loss include:

What underlying health conditions can cause osteoporosis?

Several underlying conditions can increase a person’s risk of developing osteoporosis, including:

  • rheumatoid arthritis, inflammatory bowel disease, and other autoimmune disorders
  • HIV or AIDS
  • endocrine and hormonal conditions
  • certain cancers
  • anorexia
  • gastrointestinal conditions such as celiac disease

Osteoporosis is a condition where the density or formation of bones weakens their overall strength. It can increase a person’s risk of fractures.

There is some evidence connecting its development to the immune system and autoimmune disorders. However, osteoporosis is a bone disease, not an autoimmune disorder.

Several autoimmune conditions, including rheumatoid arthritis and psoriatic arthritis, can increase a person’s risk of developing osteoporosis, as can other conditions affecting hormones, the GI tract, and other parts of the body.

It is best for a person to contact their doctor if they have concerns about conditions that can increase their risk of osteoporosis.