Causes and Risk Factors of Bone Diseases

From bone fractures (bone breaks) to crippling arthritis, disorders that affect your bones come in many forms. Any number of bone diseases can lead to abnormalities in bones and joints, increase your risk for fractures, and cause chronic pain and disability.

Genetics, age, hormones, occupation, activity levels, lifestyle, and environmental factors all play a role in the development of bone disease. Here is what you need to know about the common causes and risk factors of various bone diseases.

Common Causes

There are many different types of bone diseases. Some of these conditions affect mostly adults, while others are considered childhood bone diseases. But many of these conditions can develop regardless of age and are attributed to different causes and risk factors other than age or in addition to age.

The most common causes of bone disease are:

• Genetics
• Age
• Sex
• Ethnicity
• Occupation
• Environmental factors
• Bacteria
• Injury and overuse
• Inflammatory arthritis
• Diabetes and hormone disorders

Genetics

Many diseases of the skeletal system are considered congenital because they are either evident at birth or manifest soon after birth. Of course, that doesn’t mean that all congenital bone diseases are a result of genetics. Some congenital conditions are caused by factors related to pregnancy, delivery, and early infancy.

Genetic factors play a role in many diseases and often the factors associated with genetic bone diseases are unknown and predictable. In fact, many bone conditions are associated with family history and can be inherited across generations of one family. More on the genetics of bone disease is covered in detail below.

Age

Changes to bone health are common as you age. Osteoporosis, a condition in which bones become weak and brittle, is often diagnosed in older adults because of reduced bone density causing bones to break more easily. Muscle weakness can also contribute to the instability of bones.

Aging is also a primary cause for the development of osteoarthritis (OA), a wear and tear type of arthritis where the flexible tissue—called articular cartilage—at the ends of bones breaks down. Because cartilage cannot regenerate, aging starts a destructive pattern of changes that eventually lead to permanent bone and joint damage. 

Ethnicity and Race

There are differences in bone diseases between ethnic groups. Many of these are related to body size and composition. Most studies related to ethnicity and bone disease are linked to bone mineral density although many of these studies do not correlate with fracture rates. Nonetheless, ethnicity does affect bone structure and strength.

Some genetic bone diseases—like Paget’s disease of bone, a bone disease that disrupts the replacement of old bone tissue with new tissue—are common among ethnic groups.

Paget’s disease of bone affects people of all ethnic and racial groups, but it seems to affect people of Asian descent less frequently. The disease seems to be more common in Whites while less common in Blacks.

Sex

It seems women have a higher risk of inflammatory arthritis diseases, osteoarthritis, and osteoporosis. Inflammatory arthritis is the term used to describe a group of arthritis conditions caused by an overactive system. Inflammatory arthritis conditions include psoriatic arthritis, RA, ankylosing spondylitis, and lupus.

Many of these conditions are marked by inflammation of the joints, resulting in joint pain and stiffness. Inflammatory arthritis conditions also affect other connective tissues, including the lungs, heart, skin, eyes, and other organs. These types of arthritis can lead to irreversible damage.

Inflammatory arthritis conditions are known for affecting more women than men. The lifetime risk for developing RA is 3.6% for women and 1.7% for men.

Osteoarthritis is more common in women due to biomechanics and hormones. In terms of biomechanics, the unique function and motion of women’s joints, including having wider hips, more flexible joints, hypermobility (double-jointedness), and childbirth all contribute to the risk for OA.

Reduced hormones—specifically estrogen and testosterone—are believed to play a role in the development of OA in women. In fact, the rate of OA shoots up after menopause—the time in a person's life when their period stops.

Reduced testosterone, which women already have low amounts of, puts women at risk for OA because testosterone would generally help build and strengthen the muscle to support joints and lower the risk for OA.

Being female is also a risk factor for osteopenia and osteoporosis. This is because women have small bones and lose bone density because of reduced estrogen as they get older. Osteopenia occurs when the body doesn't make new bone as quickly as it reabsorbs old bone, eventually resulting in low bone mass and weak bones.

Occupation

Occupational bone diseases are rare although osteoarthritis has some occupational risk associated with it. Having a physical workload is one of the common occupational risk factors for OA.

Other job risk factors that contribute to OA include regular kneeling, stair climbing, bending, and repetitive movements. Also, having a genetic disposition for OA will increase any occupational risk hazard for the condition.

Other occupational hazards for bone diseases include those in occupations where a person can be exposed to noxious agents like those used in landscaping work. RA has been linked to job toxin exposure. A 2017 report in the journal Arthritis & Care finds this type of occupational exposure is a dominant risk factor for RA.

Environmental Factors

Exposure to certain toxins can affect bone health. This includes exposure to heavy metals, fungal toxins, asbestos, chlorine, environmental pollutants, nicotine, and occupational chemical exposure.

For example, autoimmunity related to inflammatory arthritis is attributed to exposure to toxic chemicals and environmental toxins. Bisphenol A (BPA) is one toxin known for triggering inflammatory arthritis and other autoimmune diseases (conditions triggered by an interactive immune system). BPA is found in many types of consumer products.

Bacteria and Infections

Infectious bone diseases—like osteomyelitis—are caused by bacteria. Common bacteria associated with bone infections are Staphylococcus bacteria. Bacterial infections of bone or bone marrow can be quite dangerous, especially if left untreated.

Infections can also contribute to some types of inflammatory arthritis. A 2014 report in the Journal of Clinical and Cellular Immunology suggests infection can trigger RA if part of the immune system loses its ability to fight bacteria or infections, if the infection causes the immune system to become overactive, or the immune system’s response to infection is to attack parts of the body.

Injury and Overuse

Many types of joint and bone injuries can increase your risk of developing OA, especially those associated with joint instability, i.e. dislocations and ligament tears. Bone and joint injuries can also result from overuse and even misuse over long periods of time.

Inflammatory Arthritis

Some types of inflammatory arthritis can contribute to the development of other bone conditions, including osteoarthritis, osteoporosis, and osteopenia.

Osteoarthritis can occur when inflammatory arthritis causes joint damage and cartilage breakdown. RA is most often connected to OA over other forms of inflammatory arthritis.

The link between osteoporosis and inflammatory arthritis has to do with bone loss. Inflammatory arthritis causes bone loss through localized bone erosion in and around an inflamed joint. The highest risk for osteoporosis and osteopenia seems to be the connection both these conditions have to RA.

Diabetes and Other Hormone Diseases

Diabetes and other hormone disorders can lead to inflammation that eventually causes osteoarthritis. Uncontrolled diabetes can lead to the breakdown of bones and joints, and cause OA and osteoporosis. People with diabetes, especially those with type 1 diabetes, tend to have lower bone quality and increased risk for fractures.

Hormone disorders can also affect the human skeleton. Overactive parathyroid glands or hyperparathyroidism, for example, can lead to excessive bone breakdown and increase your risk for fractures.

No Known Causes

Some bone diseases are idiopathic—that is, their causes or processes are unknown. Two childhood bone diseases with no known cause are idiopathic juvenile osteoporosis (IJO) and adolescent idiopathic scoliosis.

IJO causes little bone formation, excessive bone loss, or both. Adolescent idiopathic scoliosis causes an abnormal spine curvature that occurs in late childhood or adolescence.

Genetics

Metabolic bone diseases—like osteogenesis imperfecta, osteomalacia, and skeletal dysplasia—are inherited through Mendelian patterns of inheritance where a condition is acquired from a single, specific gene. Over 500 bone and joint conditions can be inherited through a Mendelian pattern.

Skeletal dysplasia includes over 450 conditions like osteogenesis imperfecta, achondroplasia, and other types of dwarfism, and hypochondroplasia. These genetic bone conditions are caused by mutations passed down from parents to children, which prevent a child’s bones from developing and growing normally.

Skeletal dysplasia isn’t always inherited, and a child can develop the condition from a new gene mutation acquired during fetal development.

Osteoporosis, a bone disease that makes bones weaker and brittle, and osteopenia, a precursor to osteoporosis marked by low bone density, are determined by several genes.

Very rarely is osteoporosis related to one single gene. The genes that cause low bone density are acquired through polygenic inheritance, where a single trait is controlled by two or more different genes.

An inheritance pattern for inflammatory arthritis is unclear because many genetic and environmental factors play a part in the development of these conditions. However, it is not unusual to have more than one family member to have the same type of inflammatory arthritis.

People can inherit the risk of developing OA, but not the condition itself. And this risk can be passed down through generations of families. Researchers don’t know if an actual inheritance pattern for OA exists.

Lifestyle Risk Factors

Lifestyle risk factors that can contribute to bone diseases include an unhealthy diet, a sedentary lifestyle, excess body weight, smoking, excessive use of alcohol, and the use of some types of medications.

Unhealthy Diet

Having a diet low in calcium or vitamin D can increase your risk for osteopenia or osteoporosis. Calcium is an essential nutrient for healthy bones, while vitamin D is necessary for calcium absorption. Reduced calcium intake contributes to reduced bone density, early bone loss, and increased risk for fractures.

Certain substances in foods can trigger RA and other types of inflammatory arthritis, according to a study reported in 2018 by the journal Frontiers in Cellular and Infection Microbiology. Researchers further note the bacteria found in milk and beef may trigger RA in people who have a genetic risk for the condition.

A Sedentary Lifestyle

People who spend a lot of time sitting have a higher risk for arthritis and osteoporosis this compared to more active people. In fact, physical inactivity contributes to many chronic diseases and can be detrimental to your health.

Body Weight

Keeping a healthy weight can help you to manage your bone health. For example, being just 10 pounds overweight can increase the force on your knees by up to 40 pounds with every step you take, according to Johns Hopkins Arthritis Center.

Smoking

Smoking is a risk factor for osteoarthritis, inflammatory arthritis, and low bone density conditions. Smoking can also increase the risk of fractures and the time it takes to heal from a fracture.

Excessive Use Of Alcohol

Research shows heavy alcohol consumption contributes to decreased bone remodeling, increases fracture risk, and can delay the healing of fractures. This is because alcohol can interfere with the balance of calcium and the production of vitamin D.

Some Medications

Long-term use of certain medications can make it harder to absorb and lead to damage to bones. Examples of medications that can damage bones include corticosteroids used to treat inflammatory arthritis, selective serotonin reuptake inhibitors for treating mood disorders, some anti-seizure medications, hormonal contraceptives, and proton pump inhibitors used to reduce stomach acid.

A Word From Verywell

Causes of bone diseases are many and often, more than cause or risk factors can is associated with a bone disease. Some of these causes and risk factors are unavoidable, but some, including lifestyle risk factors, are within your control and by taking certain actions, you can reduce your risk for some types of bone diseases.

If you are concerned about your bone health or risk factors for bone diseases, talk to your healthcare provider. They can request various tests—including a genetic screening or a bone density test—to determine your risk and suggest ways to reduce risk factors.