Arthritis: Types, Symptoms, Causes, and Treatment

"Arthritis" literally means joint inflammation, but it's used as an umbrella term for more than 100 distinct conditions that affect the joints in different ways — including the colloquial term "rheumatism," which is largely synonymous with arthritis in everyday usage rather than a distinct medical diagnosis.

Quick Answer

Arthritis is not one disease — it's a general term for conditions that cause joint pain, stiffness, or swelling. Osteoarthritis (gradual cartilage wear), inflammatory types like rheumatoid arthritis (the immune system attacking the joints), and gout (uric acid crystal buildup) are different conditions with different causes and different treatments. Most joint pain is not an emergency, but sudden swelling, redness, or warmth in one joint with fever needs prompt same-day evaluation.

What Is Arthritis?

Arthritis means inflammation of a joint — the places where two bones meet, such as the knee or elbow. The NIH's National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS) describes it this way and lists several distinct conditions under the arthritis umbrella, each with its own cause, pattern, and treatment. Because the word covers so much ground, an accurate diagnosis — not just the label "arthritis" — is what actually guides treatment.

Main Types of Arthritis

Osteoarthritis is the most common type and is more common in older people. It develops from gradual breakdown of the cartilage that cushions joints, most often affecting weight-bearing joints like the knee, hip, and spine, as well as the hands. Our knee osteoarthritis guide covers the most commonly affected joint in depth, and our knee osteoarthritis treatment guide covers treatment options specifically.

Rheumatoid arthritis is an autoimmune form of arthritis in which the immune system attacks healthy joint tissue, causing inflammation that can affect many joints, often on both sides of the body. It is not a "wear and tear" condition, and it typically needs medication that targets the immune system rather than measures aimed at mechanical joint damage.

Gout happens in flares, typically in the big toe or another joint in the lower limb, caused by uric acid crystals building up in the joint. It has its own dedicated gout guide given how different its triggers and treatment are from the other types.

Psoriatic arthritis affects the skin, the joints, and the areas where tendons and ligaments attach to bone, and often occurs in people who already have psoriasis.

Other recognized types include ankylosing spondylitis, which causes inflammation in the joints and ligaments of the spine; juvenile idiopathic arthritis, the most common form of chronic arthritis in children; and reactive arthritis, triggered by an infection elsewhere in the body, which often clears on its own within weeks to months.

A regionally relevant cause worth knowing: recurrent joint attacks, especially in children or young adults, can also stem from Familial Mediterranean Fever, a hereditary condition more common in this part of the world — distinct from osteoarthritis and typically identified by its accompanying fever pattern rather than joint imaging alone.

Common Arthritis Symptoms

NIAMS lists pain, redness, heat, and swelling in the joints as common symptoms across arthritis types. Stiffness and a reduced range of motion are also common. Some inflammatory types also cause symptoms beyond the joints, such as fatigue or fever, because the underlying immune activity affects more than just one area.

How Symptoms Differ by Type

The specific pattern — which joints, how symmetric, how quickly it develops, and what else comes with it — helps distinguish between types, though it is a clue for a doctor to interpret, not a self-diagnosis tool:

• Osteoarthritis tends to affect specific, often weight-bearing joints, is not necessarily symmetric (one knee can be affected more than the other), and morning stiffness is usually brief, typically easing within around 30 minutes.
• Rheumatoid arthritis classically affects the same joints on both sides of the body, and morning stiffness tends to last longer — often more than an hour — and eases slowly rather than quickly with movement. Joints may also feel warm and swollen, and fatigue or low-grade fever can occur.
• Gout causes sudden, intensely painful flares, often in a single joint such as the big toe, rather than a gradual onset.

Arthritis Causes and Risk Factors

Causes differ by type: osteoarthritis relates to mechanical wear, joint injury, and age-related changes in cartilage; rheumatoid and psoriatic arthritis are autoimmune; gout relates to uric acid levels; and reactive arthritis follows an infection. Risk factors that can apply more broadly include older age, previous joint injury, excess weight (which adds mechanical load to weight-bearing joints), a family history of some arthritis types, and — for autoimmune types — genetic and immune factors that are not within a person's control. Arthritis cannot always be prevented, especially the autoimmune types, though managing modifiable factors such as weight and joint injury risk can help with osteoarthritis specifically.

Osteoarthritis vs Inflammatory Arthritis

These are fundamentally different processes, not two names for the same thing. Osteoarthritis is a mechanical, degenerative process centered on cartilage breakdown. Inflammatory arthritis, including rheumatoid and psoriatic arthritis, is driven by immune system activity that causes inflammation in the joint lining, and can have effects elsewhere in the body. This distinction is why osteoarthritis treatment focuses on mechanical load, pain, and function, while inflammatory arthritis treatment focuses on controlling the underlying immune activity, often with specific medications prescribed and monitored by a rheumatologist.

Arthritis in Different Age Groups

Osteoarthritis becomes more common with age, though injury can bring on earlier changes in a specific joint. Rheumatoid arthritis and other autoimmune types can begin at almost any age, including in young adults. Juvenile idiopathic arthritis is, by definition, a childhood-onset condition, and Familial Mediterranean Fever attacks often begin in childhood or early adulthood. Age is a useful general clue but never a substitute for an actual evaluation.

How Arthritis Is Diagnosed

Diagnosis usually combines the story of the symptoms with examination and, often, tests — no single test "proves" most types of arthritis on its own.

Physical Examination

A doctor examines which joints are affected, whether the pattern is symmetric, and looks for swelling, warmth, redness, and the joint's range of motion, along with checking for signs outside the joints relevant to some types, such as skin changes in psoriatic arthritis.

Blood Tests

Blood tests can support a diagnosis depending on what's suspected: markers of inflammation (such as ESR or CRP), antibodies associated with rheumatoid arthritis, and uric acid levels when gout is suspected. Blood tests are supportive evidence, not a stand-alone diagnosis — a normal result does not fully rule out a condition, and an abnormal one does not fully confirm it, which is why they're interpreted alongside the clinical picture.

Imaging

X-rays can show joint damage typical of osteoarthritis or longer-standing inflammatory arthritis, while ultrasound or MRI can sometimes detect inflammation earlier, before changes are visible on an X-ray.

Arthritis Treatment

Treatment depends heavily on the specific type, which is why an accurate diagnosis matters more than the general label "arthritis."

Exercise and Physical Activity

For osteoarthritis, regular exercise and staying active — rather than resting the joint completely — is a core, first-line part of management, since it helps maintain muscle support around the joint and overall function. For inflammatory types, staying appropriately active is also encouraged alongside medical treatment, generally guided by how active the disease is at the time.

Weight Management

For osteoarthritis affecting weight-bearing joints, reducing excess weight lowers the mechanical load on the joint and is one of the more effective, broadly beneficial interventions available.

Medicines

Osteoarthritis pain is often managed with topical or oral anti-inflammatory medication, used carefully because of their risks with regular long-term use. Inflammatory types like rheumatoid arthritis typically need disease-modifying medication that targets the immune system, prescribed and monitored by a rheumatologist — these are a different category of treatment from simple pain relief, aimed at controlling the underlying disease process. Gout has its own specific medication approach, covered in our gout treatment guide.

Physical Therapy

A physical therapist can build a program of targeted exercises and movement strategies suited to the specific joint and type of arthritis, which helps many people maintain function over the long term.

When Joint Pain Could Be an Emergency

When to See a Doctor

See a doctor for joint pain that is new, persistent, or affecting daily activities; for morning stiffness lasting longer than about an hour; for swelling that doesn't settle; or for joint symptoms that come with fatigue, skin changes, or fever outside of the emergency pattern above. Getting an accurate type of arthritis identified early generally leads to more effective treatment, especially for inflammatory types.

How Arthritis Can Be Managed Long Term

Most people with arthritis, across types, can lead active lives with appropriate long-term management — NIAMS notes that current treatments allow most people with arthritis to stay active and productive. For osteoarthritis, this generally means an ongoing combination of activity, weight management, and pain control, adjusted over time. For inflammatory types, it means staying on and periodically reviewing disease-modifying treatment with a rheumatologist, since the goal is to control inflammation before it causes further joint damage, not just to treat pain when it flares.

Related Conditions and When Another Diagnosis May Be More Likely

Not every joint pain is arthritis. Injuries, tendon problems (such as shoulder tendonitis), bursitis, and referred pain from other structures can all cause joint-area pain without true joint inflammation. Familial Mediterranean Fever should be considered for recurrent fever-plus-joint-attack patterns, especially in this region. If pain is clearly linked to a specific recent injury, or is isolated to tendons or soft tissue around a joint rather than the joint itself, a non-arthritis diagnosis may be more likely — a doctor can help tell the difference.

Sources

• Arthritis — NIH/NIAMS
• Septic arthritis — NHS
• Familial Mediterranean Fever — MedlinePlus