What Is Osteoarthritis (OA)?

Have you ever wondered what happens when your joints feel stiff, sore, or don’t move as easily as they should? It could be something called osteoarthritis, or OA for short. OA is the most common type of arthritis. It doesn’t just affect one part of your joint—it involves the entire joint, including:

Bone 🦴
Cartilage (the smooth cushion between bones)
Ligaments (the bands holding your joint together)
Fat and the tissues that line the joint (called the synovium)

When OA happens, the cartilage gets thinner and rougher, and the bones in your joint can even change shape. This leads to pain, stiffness, and trouble moving.

Where Can OA Show Up?

OA can affect different parts of your body in different ways:

Hips: You might feel pain in your groin, thigh, or even your butt.
Knees: Moving your knee might feel like there’s sand inside—scratchy and rough.
Fingers: Joints can become swollen, red, or bumpy, making tasks like writing or typing harder.
Feet: Your big toe or ankle might hurt when walking or standing.

What Happens to Your Joints in OA?

Normally, your joints repair themselves when they’re a little damaged. But sometimes, the repair process changes the shape or structure of the joint. This can lead to:

Hard swelling: Bony bumps called osteophytes grow at the edge of the joint.
Soft swelling: Extra fluid builds up, making the joint puffy (like water on the knee).

These changes make your joints feel rough instead of smooth, so movements like walking or bending can hurt.

How Will OA Affect You?

OA doesn’t happen all at once. Symptoms sneak up slowly. Here’s what you might notice:

Morning stiffness: Joints feel achy when you wake up or after sitting for a long time.
Swelling or larger joints: Your joints might look bigger.
Weak muscles: You could feel less strong or even wobbly, especially in your knees.
Noisy joints: Hear crunching or cracking when moving? That’s OA saying hello.
Unsteady joints: Sometimes a knee might feel like it’s about to give out.

The symptoms can range from mild to severe. Some people hardly notice OA, while others might have a hard time doing everyday activities, like climbing stairs or opening jars.

Where Else Can OA Show Up?

OA can affect different parts of your body in different ways:

Hips: You might feel pain in your groin, butt, or even your thigh.
Knees: Moving your knee might feel like there’s sand inside—scratchy and rough.
Fingers: Joints can become swollen, red, or bumpy, making tasks like writing or typing harder.
Feet: Your big toe or ankle might hurt when walking or standing.

What Causes OA?

OA doesn’t have one single cause, but there are things that can increase your chances of getting it:

Lifestyle Factors

Extra weight: Carrying more weight puts more pressure on your joints. For example, being just 10 pounds overweight can add up to 50 pounds of extra pressure on your knees!
Weak muscles: Muscles are like the bodyguards of your joints. When they’re not strong enough, joints lose their support. This can lead to poor alignment and wear-and-tear on the cartilage.
Old injuries: Your joint might develop OA faster if you had an injury before. Around 50% of adults with ACL (anterior cruciate ligament) injuries develop knee OA within 5 to 15 years.

Genetics and Body Structure

Family history: If your parents or grandparents had OA, you might be more likely to get it too.
Joint shape: For example, there is a condition called hip dysplasia. This occurs when the top of the thigh bone doesn’t fit snugly into the hip socket. Over time, this can lead to hip OA because the cartilage wears out faster.
Age: Your joints naturally wear down over time, especially if you use them a lot.

Jobs and Activities

Your job and daily activities can affect your joint health, especially if they are physically demanding, such as repetitive movement in kneeling, squatting, or lifting. This increases the risk of OA over time.

Agricultural workers: Have up to 64% higher odds of developing OA.
Construction workers: Face 63% higher odds due to heavy lifting, kneeling, and climbing.
Houseworkers (unpaid): Surprisingly, they have the highest risk at 93%, likely due to repetitive cleaning, kneeling, and squatting.

How Common Is OA?

Prevalence of Osteoarthritis (OA) Worldwide

This map shows how common Osteoarthritis (OA) is around the world:

Dark Blue:

Red:

Osteoarthritis (OA) is incredibly common and impacts millions of people worldwide. While it’s often associated with older adults, it’s not just a “disease of aging.”

Who Gets OA?

Symptoms usually appear in individuals over the age of 45. However, 43% of people with OA are under 65, especially those who’ve had previous joint injuries like an ACL tear or meniscus damage. OA develops gradually, but for those with prior injuries, it can worsen much more quickly—sometimes in just a few years.

Worldwide Numbers:

In 2019: About 528 million people worldwide were living with OA.
57 million people in Western Europe are affected.
In the U.S., OA is the most common type of arthritis, impacting over 32.5 million adults.
In the UK: OA affects an estimated 8.75 million people over 45 years old, with 5.04 million women and 3.46 million men living with the condition.

Why Does OA Matter?

Osteoarthritis doesn’t just cause joint pain—it can impact overall health and daily life in unexpected ways.

Obesity, Diabetes, and Heart Disease

OA can make it difficult to stay active, and limited movement often leads to other health problems:

Weight Gain: Painful joints make exercise harder, leading to weight gain or obesity.
Chronic Diseases: Excess weight increases the risk of developing high cholesterol, type 2 diabetes, heart disease, and high blood pressure.

Increased Risk of Falls

People with OA are 30% more likely to experience falls compared to those without OA. Why?

Pain and Stiffness: These can disrupt your balance and walking pattern.
Deconditioning: Weak muscles and reduced joint stability make it harder to recover from stumbles.

What Can You Do About OA?

The good news? There’s a lot you can do to take care of your joints! Wondering how to manage OA and improve your quality of life? Click here to explore practical management tips for OA.

References

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