Arthritis is a common condition that causes pain and inflammation in the joints. It tends to get more common as people get older. By age 60, most people have some signs of wear and tear arthritis (osteoarthritis) on x-rays, although not everyone has symptoms. Rheumatoid arthritis, an inflammatory form of arthritis, often starts in middle age.
Some types of arthritis, especially osteoarthritis, are more likely as you get older. Other types of arthritis, such as gout and pseudogout, are more common in older adults. Old injuries to joints can also lead to arthritis later in life.
Here are some key points about what causes arthritis later in life:
Wear and tear
As people get older, their joints are more likely to show signs of wear and tear. For example, osteoarthritis results from breakdown of cartilage, the rubbery material that cushions joints. Cartilage normally allows bones to glide over each other and absorb shock. When cartilage breaks down, bones rub together, causing pain and stiffness. Osteoarthritis is the most common type of arthritis.
Injuries
Joints that have been injured in the past are more prone to develop osteoarthritis later on. For example, people who’ve had a knee injury or surgery often get arthritis in that knee joint years afterward.
Obesity
Carrying around extra body weight strains joints, especially knees and hips. Obese and overweight people have a higher risk of developing osteoarthritis in these weight-bearing joints. Losing weight can relieve arthritis pain by reducing this mechanical stress on joints.
Genetics
Genes play a role in osteoarthritis. For example, defects in collagen genes can lead to defects in collagen, an important building block of cartilage. People born with these defects may get osteoarthritis earlier in life. Genes also make some people more prone to injuries that lead to arthritis later on.
Immune system disorders
Rheumatoid arthritis happens when the immune system attacks the joints. It’s not fully understood why the immune system malfunctions in this way, but genes are thought to play a role. Rheumatoid arthritis often starts between ages 30-50.
Metabolic disorders
Gout is caused by excess uric acid in the blood. The uric acid forms needle-like crystals that build up in joints, causing sudden attacks of severe pain and swelling. Gout becomes more common with age due to less efficient kidney function and other age-related metabolic changes.
Underlying Mechanisms
Although we know some of the general factors that cause arthritis later in life, the underlying biological mechanisms are complicated and not fully understood. Here is more detail about processes that contribute to arthritis in older adults:
Osteoarthritis
Osteoarthritis develops when cartilage breaks down faster than the body can repair it. Cartilage has no blood vessels, so damage is difficult to heal. With advanced age, cartilage weakens due to:
- Accumulation of enzymes that degrade cartilage
- Decline in growth factors needed for repair
- Reduced ability of cartilage cells (chondrocytes) to multiply and maintain cartilage
In addition, low-grade inflammation in aging joints produces chemicals that degrade cartilage. Breakdown products from cartilage can also cause inflammation.
Rheumatoid Arthritis
Immune cells called lymphocytes become overactive, moving into joints and releasing inflammatory chemicals. Chemical signals called cytokines act on the lymphocytes and other cells to perpetuate inflammation. Genetic risks plus unknown triggers lead to immune system malfunction.
Gout
Excess uric acid forms needle-like crystals that accumulate in joints. Uric acid production is often higher in older people due to impaired kidney function. Metabolic disorders like obesity and insulin resistance also contribute. Crystals cause inflammation when immune cells try to clear them.
Osteoporosis
With advanced age, bones tend to become less dense and weaker due to lower estrogen levels and reduced physical activity. Weak bones are more prone to fractures. Arthritis is common after fractures involving joints because the injury alters normal joint structure.
Risk Factors
Certain factors increase your risk of developing arthritis as you age:
Age
Osteoarthritis risk rises starting around age 45 and peaks at age 65. More than 30% of 65-74 year-olds have osteoarthritis. Rheumatoid arthritis often begins between ages 30-50. Gout becomes more common in men over age 40 and women over 50.
Obesity
Extra weight strains the knee joint in particular. Obese people have up to 4 times the risk of knee osteoarthritis compared to normal weight individuals. Losing weight reduces arthritis progression and symptoms.
Injury
Joints injured earlier in life are more prone to osteoarthritis. Knee injuries increase risk of later knee osteoarthritis. People who had surgery on a joint have higher risk of osteoarthritis in that joint.
Genetics
Genes can make people more susceptible to osteoarthritis, rheumatoid arthritis, gout, and injuries/weak bones that lead to arthritis. Family history of arthritis increases your risk.
Repetitive physical work
Certain occupations involve repetitive knee bending and squatting. This mechanical stress increases risk for later knee osteoarthritis. Examples are construction, plumbing, electrical work.
Smoking
Smoking is linked to more severe rheumatoid arthritis symptoms. It may also contribute to osteoarthritis development. Smokers tend to have weaker bones (osteoporosis).
| Risk Factor | How it Increases Arthritis Risk |
|---|---|
| Age over 45 | Increased wear and tear, metabolic changes |
| Obesity | Mechanical stress on joints |
| Joint injury | Alters joint structure |
| Genetics | Increases susceptibility |
| Repetitive joint use | Mechanical wear and tear |
| Smoking | Impairs bones, worsens inflammation |
Prevention
You can lower your risk of arthritis later in life by:
- Maintaining a healthy weight to reduce joint stress
- Avoiding injuries through proper training, technique, and equipment for sports/occupation
- Quitting smoking to avoid damaging bones and joints
- Doing low-impact aerobic and muscle-strengthening exercise
- Using proper form and body mechanics for lifting and repetitive tasks
If you already have mild arthritis symptoms, early treatment can often reduce pain and disability. Losing weight, exercise, braces, medications, and even surgery in some cases, can help keep joints healthy.
Outlook
Many types of arthritis become more common with age. While we don’t know how to prevent arthritis completely, we do know steps to lower the risk. Staying active and maintaining a healthy weight reduces wear and tear on joints. Early treatment can limit damage from arthritis that develops later on. Research into regenerative treatments may someday help reverse arthritis.
Conclusion
Arthritis in older adults results from both normal wear and tear as well as specific diseases that damage joints. Osteoarthritis develops from breakdown of cartilage and bone changes. Rheumatoid arthritis is caused by the immune system mistakenly attacking joints. Gout arises from excess uric acid crystals in joints. Injuries earlier in life can also lead to arthritis later on. Staying active and avoiding obesity are key preventive steps. Early treatment helps limit damage from arthritis that does develop with age. While more research is still needed, our expanding knowledge offers hope for future improvements in arthritis prevention and treatment.