Arthritis isn’t a single disease but a term for joint pain or disease. It’s a complex condition with a wide range of manifestations. According to the Arthritis Foundation, there are more than 100 types of arthritis and related conditions, each with its unique characteristics and impact on the body.
Common arthritis symptoms include swelling, pain, stiffness, and diminished range of motion in joints. It’s important to note that symptoms vary from mild to severe and may come and go. Some may stay about the same for years, but it’s crucial to know that symptoms can progress and worsen over time.
Severe arthritis can result in chronic pain and difficulty performing daily activities, making walking and climbing stairs painful and grueling.
Arthritis is not just about joint pain. It can also lead to permanent joint changes, some of which may be visible, such as knobby finger joints. However, often the damage is only detectable on X-rays. Moreover, some types of arthritis can affect other organs, including the heart, eyes, lungs, kidneys, skin, and joints.
There are three main types of arthritis: rheumatoid, psoriatic, and osteoarthritis. Although they share similar symptoms, these three conditions have distinct causes, occur in people of varying ages, and have their own treatments.
We’ll take a look at the key differences between the three.
What Is Osteoarthritis?
Osteoarthritis is the most common type of arthritis, affecting 528 million people worldwide. It happens when cartilage, the rubbery connective tissue covering the ends of bones in your joints, breaks down.
Historically, osteoarthritis was thought to be a byproduct of aging, according to the Centers for Disease Control. However, experts now consider it to be a disease affecting the entire joint that doesn’t necessarily stem from getting older. It’s not just cartilage and bone that are impacted but ligaments, fat, and other tissues lining the joint.
Factors that can lead to osteoarthritis include injuries, overuse of joints, age, genetics, and obesity. Women are more likely to develop the condition, especially once they reach 50. Though osteoarthritis is associated with older adults, it’s not inevitable; some never develop the condition.
The most common symptoms are pain while using the joint, stiffness (especially after a period of rest), swelling, reduced flexibility, and hearing the joint click or pop. Osteoarthritis can affect any joint but frequently strikes the hands, hips, knees, neck, and lower back.
Because it’s a degenerative condition, it typically worsens over time. As cartilage becomes degraded, the bone can change shape or develop small bony growths known as bone spurs on the affected joint, causing pain and increasing the likelihood of disability.
There’s no cure for osteoarthritis, but the pain and inflammation can be managed with over-the-counter or prescription medications—such as pain relievers and nonsteroidal anti-inflammatory drugs (NSAIDs). Exercise and weight loss may also help the condition.
What Is Rheumatoid Arthritis?
Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disorder that impacts 18 million people around the globe, affecting nearly three times as many women as men. It occurs when the immune system mistakes specific healthy cells in the body as invaders and goes on attack. In RA, the immune system attacks the synovium, the tissue surrounding a joint that produces fluids to help it move smoothly.
When this happens, cytokines, the signaling proteins that help control inflammation, increase. The inflamed synovium thickens, making the joint red, swollen, and painful to move. Over time, this may ultimately lead to structural damage and joint destruction.
Signs of RA include stiffness, pain, and swelling in multiple joints. Patients tend to have the same symptoms on both sides of the body, such as both hands or knees. In some cases, RA affects other parts of the body, causing skin conditions, digestive issues, fatigue, eye problems, and heart and lung conditions.
The exact cause of RA is unknown, but it’s likely linked to genetics. It can occur at any age, but the risk increases as people age. Some research shows that smoking may raise the risk for RA.
When diagnosing RA, doctors rely on blood tests to look for inflammation and antibodies, or blood proteins, that are signs of the condition. Physicians might also take X-rays, ultrasounds, or MRIs to identify evidence that the joint is wearing away.
To treat RA, doctors typically prescribe disease-modifying anti-rheumatic drugs (DMARDs), which modify the immune system and slow the disease’s progression.
What Is Psoriatic Arthritis?
Psoriatic arthritis (PsA) is also a chronic autoimmune disease, causing the immune system to attack the body’s healthy tissue, including tissue of the skin and joints. It’s commonly linked with the skin condition psoriasis; about a third of patients with psoriatic arthritis develop psoriatic arthritis. Roughly 125 million individuals worldwide have the condition, and it can start at any age, even in childhood.
PsA specifically affects the joints and the junctions between the bone and the tendon near the joint, what is called enthesis. It is often found in the hands, feet, wrists, ankles, and knees.
Like other forms of arthritis, PsA causes pain, stiffness, swelling, and a reduced range of motion. However, it can also result in silver or gray scaly spots on the scalp, elbows, knees, and lower spine, as well as nail depressions or detached fingernails or toenails.
Left untreated, psoriatic arthritis can damage or weaken bones and lead to vision problems, gastrointestinal conditions, shortness of breath, and damage to blood vessels and heart muscles.
Like RA, the cause of PsA isn’t known, but it’s believed to be a combination of genetic and environmental factors—such as an infection, for example—that can trigger a flare-up of symptoms. Doctors diagnose the condition using blood tests, X-rays, MRIs, and a physical exam.
Both psoriatic and rheumatoid arthritis can be challenging for patients to distinguish since the symptoms are similar. However, it’s crucial to seek treatment when you notice joint swelling and pain, as all three types of arthritis can lead to long-term joint damage and other health consequences.