Arthritis describes over 100 different conditions that involve inflammation of any part of a joint, including the joint lining (synovium), cartilage, bones, and supporting tissues.
Osteoarthritis is the most common type of arthritis that often develops with age. It is a chronic condition in which the cartilage between bones that cushions the joints wears down and as it does, the bones rub against each other, causing pain, stiffness, swelling, and reduced joint motion.
Other types of arthritis include:
- Rheumatoid arthritis (RA)
- Psoriatic arthritis
- Childhood arthritis
- Infectious arthritis
- Gout
- Systemic lupus erythematosus (SLE)
- Fibromyalgia
What Are Symptoms of Arthritis and Osteoarthritis?
The main symptom of most types of arthritis, including osteoarthritis, is joint symptoms, such as:
- Pain
- Swelling
- Stiffness
- Tenderness
- Warmth
- Redness
- Limited movement/decreased range of motion or flexibility
Depending on the type of arthritis, other symptoms that can accompany joint symptoms include:
- Fever
- Fatigue
- Headaches, including migraines
- Numbness or tingling in hands and feet
- Weakness
- Weight loss
- Anxiety
- Depression
- Difficulty sleeping
- Problems with thinking, concentration, and memory
- Pain in the face or jaw, including temporomandibular joint syndrome (TMJ)
- Digestive problems, such as abdominal pain, constipation, bloating, and irritable bowel syndrome (IBS)
What Causes Arthritis and Osteoarthritis?
There is no one main cause for arthritis, and causes depend on the type of arthritis.
Causes and risk factors for osteoarthritis include:
- Advancing age
- At least 80% of people over age 55 have some X-ray evidence of osteoarthritis
- Gender
- Women are two to three times more likely than men to develop osteoarthritis
- Joint injury or trauma
- Occupations that require frequent squatting and kneeling
- Obesity
- Sports such as boxing, wrestling, pitching in baseball or softball, cycling, ice hockey, soccer, gymnastics, and football
How Are Arthritis and Osteoarthritis Diagnosed?
Forms of arthritis, including osteoarthritis, are diagnosed with a medical history and physical examination along with laboratory and imaging tests such as:
- Blood tests
- Rheumatoid factor (RF)
- Antinuclear antibody (ANA) for SLE
- Anti-cyclic citrullinated peptide (CCP)
- Arthrocentesis (also called joint aspiration or joint tap)
- X-rays (also used to monitor changes in the joint over time)
- Magnetic resonance imaging (MRI)
- Computed tomography (CT) scan
- Ultrasound
What Is the Treatment for Arthritis and Osteoarthritis?
Treatment for osteoarthritis and other forms of arthritis may include lifestyle modifications, medications, and/or surgery.
Lifestyle modifications to treat osteoarthritis include:
- Exercise programs
- Weight loss if needed
- Physical and occupational therapy
- Orthoses such as splints and braces
- Assistive devices such as canes, walkers, raised toilet seats, tub and shower bars, and electric-powered seat lifts
- Arthritis education and support
Medications used to treat osteoarthritis include:
- Topical therapies
- Pain relievers such as nonsteroidal anti-inflammatory drugs (NSAIDs) and acetaminophen (Tylenol)
- Medications that suppress the immune system (such as prednisone or methotrexate)
- Antibiotics for bacterial joint infections
Surgery is a last resort used when severe osteoarthritis does not respond to other treatments and significantly limits a person’s activities.
From 
Image source: iStock Images
https://www.uptodate.com/contents/arthritis-beyond-the-basics?search=Arthritis&source=search_result&selectedTitle=9~150&usage_type=default&display_rank=9
https://www.cdc.gov/arthritis/basics/types.html
https://www.uptodate.com/contents/osteoarthritis-symptoms-and-diagnosis-beyond-the-basics?search=Osteoarthritis&source=search_result&selectedTitle=4~150&usage_type=default&display_rank=4
https://www.uptodate.com/contents/rheumatoid-arthritis-symptoms-and-diagnosis-beyond-the-basics?search=rheumatoid%20arthritis&source=search_result&selectedTitle=5~150&usage_type=default&display_rank=5
https://www.uptodate.com/contents/psoriatic-arthritis-beyond-the-basics