02/01/2026
Types of Arthritis — Explained Simply
Arthritis is not one single condition. It’s a group of joint disorders with different causes, symptoms, and treatments. Knowing the type matters, because what helps one kind may not work for another.
Here are the main types of arthritis, explained clearly and simply.
1. Osteoarthritis (OA)
Most common type
Caused by wear and tear of joint cartilage
Cartilage gradually breaks down over time
Commonly affects
Knees
Hips
Spine
Hands
2. Rheumatoid Arthritis (RA)
Autoimmune disease
The immune system mistakenly attacks the joint lining
Leads to inflammation and joint damage
Key feature
Often affects both sides of the body (both hands, both knees)
3. Psoriatic Arthritis
Inflammatory arthritis linked to psoriasis
Swollen fingers or toes (“sausage digits”)
Nail pitting or ridging
Usually occurs in people with psoriasis, a chronic skin condition.
4. Gout
Sudden and very painful form of arthritis
Caused by uric acid crystal buildup in joints
Often starts in the big toe
Attacks can come on quickly, often overnight.
5. Ankylosing Spondylitis
Inflammatory arthritis affecting the spine
Causes chronic back pain and stiffness
Over time, spinal bones may fuse
This can reduce flexibility and lead to a stooped posture.
6. Juvenile Idiopathic Arthritis (JIA)
Arthritis in children under age 16
Joint swelling, pain, and stiffness
Can affect growth if not treated early
7. Septic (Infectious) Arthritis
Medical emergency
Caused by a bacterial or viral joint infection
Rapid pain, swelling, and fever
Requires urgent treatment to prevent permanent joint damage.
Why this matters
Different types have different causes
Treatments vary widely
Early diagnosis improves long-term outcomes