What is arthritis?

Arthritis is a joint disorder featuring inflammation. A joint is an area of the body where two different bones meet. Joint functions to move the body parts connected by their bones. Arthritis literally means inflammation of one or more joints.
Arthritis is frequently accompanied by joint pain. Joint pain is referred to as arthralgia. When four or more joints are involved, the arthritis is referred to as polyarthritis. When two or three joints are involved, it is referred to as oligoarthritis. When only a single joint is involved, it is referred to as monoarthritis.
How many types of arthritis exist?
There are many types of arthritis (over 100 identified). The types of arthritis range from those related to wear and tear of cartilage (such as osteoarthritis) to those associated with inflammation resulting from a misdirected immune system (such as rheumatoid arthritis).
What are the 3 common types of arthritis?
While osteoarthritis, rheumatoid arthritis, and gout are the three most common types of arthritis, there are many other common and uncommon types of arthritis. Other types of inflammatory arthritis include:
- Psoriatic arthritis
- Ankylosing spondylitis
- Reactive arthritis
- Infectious arthritis (septic arthritis and Lyme arthritis)
Together, the many types of arthritis make up the most common chronic illness in the United States. Self-limited forms of arthritis can occur in association with virus infections.
What causes arthritis?
The causes of arthritis depend on the type of arthritis and may include:
- Injury (leading to osteoarthritis)
- Metabolic abnormalities (such as gout with elevated uric acid blood levels and pseudogout with hypercalcemia)
- Hereditary factors
- Direct and indirect effects of infections (bacterial and viral)
- Misdirected immune system with autoimmunity (such as in rheumatoid arthritis and systemic lupus erythematosus)
Arthritis is classified as one of the rheumatic diseases. These are conditions that are different individual illnesses, with differing features, treatments, complications, and prognoses. They are similar in that they have a tendency to affect the joints, muscles, ligaments, cartilage, and tendons, and many have the potential to affect other internal body areas.
What are risk factors for arthritis?
The major risk factors for most forms of arthritis are genes that are inherited from ancestors. Trauma-related arthritis is related to the risk of injury from specific activities.
What are the symptoms of arthritis?
Symptoms of arthritis include pain and limited function of joints. Joint inflammation from arthritis is characterized by joint stiffness, swelling, redness, pain, and warmth:
- Stiffness of the joint can lead to poor function.
- Tenderness of the inflamed joint can be present with or without pain.
- When large joints are involved, such as the knee, there can be loss of cartilage with limitation of motion from the joint damage.
- When arthritis affects the small joints in the fingers, there can be bone growth and loss of hand grip and grip strength of the hand associated with stiffness.
- Arthritis of weight-bearing joints can lead to difficulty walking from poor joint function and arthritis pain.
Many forms of arthritis, because they are rheumatic diseases, can cause symptoms affecting various organs of the body that do not directly involve the joints. Therefore, symptoms in some patients with certain forms of arthritis can also include:
- Fever
- Gland swelling (swollen lymph nodes)
- Weight loss
- Fatigue
- A grating sensation or “popping” sound when the joint moves
- Feeling unwell
- Symptoms of abnormalities of organs such as the lungs, heart, or kidneys

QUESTION
The term arthritis refers to stiffness in the joints. See AnswerHow is arthritis diagnosed?
The first step in the diagnosis of arthritis is a meeting between the doctor and the patient.
- The doctor will review the history of symptoms, examine the joints for inflammation and deformity, as well as ask questions about or examine other parts of the body for inflammation or signs of diseases that can affect other body areas.
- Furthermore, medical professionals may order certain blood (C-reactive protein, sedimentation rate, rheumatoid factor, anti-CCP antibody, etc.), urine, joint fluid, and/or X-ray tests. Plain X-ray testing can be used to easily detect signs of osteoarthritis, such as joint space narrowing and spur formation (osteophytes).
- A doctor will make a diagnosis based on the pattern of symptoms, the distribution of the inflamed joints, and any blood and X-ray findings. Several visits may be necessary before the doctor can be certain of the diagnosis. A doctor with special training in arthritis and related diseases is called a rheumatologist (see below).
Many types of arthritis are more of an annoyance than serious. However, millions of people suffer daily from pain and disability from arthritis or its complications.
Earlier and accurate diagnosis can help to prevent irreversible damage and disability. Properly guided programs of exercise and rest, medications, physical therapy, and surgery options can idealize long-term outcomes for those with arthritis. Exercise and exercise routines can be helpful in providing joint stability by strengthening the musculoskeletal system while improving balance. Physical therapists can provide the care needed for properly guided exercise regimens.
It should be noted that both before and especially after the diagnosis of arthritis, communication with the treating doctor is essential for optimal health. This is important from the standpoint of the doctor so that he/she can be aware of the vagaries of the patient's symptoms as well as their tolerance of and acceptance of treatments. It is important from the standpoint of patients so that they can be assured that they have an understanding of the diagnosis and how the condition does and might affect them. It is also crucial for the safe use of medications.
What doctors treat arthritis? What is a rheumatologist?
A rheumatologist is a medical doctor who specializes in the non-surgical treatment of rheumatic illnesses, especially arthritis.
Rheumatologists have special interests in unexplained rash, fever, arthritis, anemia, weakness, weight loss, fatigue, joint or muscle pain, autoimmune disease, and anorexia. They often serve as consultants, acting like medical detectives at the request of other doctors.
Rheumatologists have particular skills in the evaluation of the over 100 forms of arthritis and have special interests in conditions that cause or are linked to inflammatory arthritis such as:
- Rheumatoid arthritis
- Seronegative arthritis
- Spondylitis
- Psoriatic arthritis
- Systemic lupus erythematosus
- Antiphospholipid syndrome
- Still's disease
- Dermatomyositis
- Sjögren's syndrome
- Vasculitis
- Scleroderma
- Mixed connective tissue disease
- Sarcoidosis
- Lyme disease
- Osteomyelitis
- Osteoarthritis
- Back pain
- Gout
- Pseudogout
- Relapsing polychondritis
- Henoch-Schönlein purpura
- Serum sickness
- Reactive arthritis
- Kawasaki disease
- Fibromyalgia
- Erythromelalgia
- Raynaud's disease
- Growing pains
- Iritis
- Osteoporosis
- Reflex sympathetic dystrophy
Classical adult rheumatology training includes four years of medical school, one year of internship in internal medicine, two years of internal medicine residency, and two years of rheumatology fellowship. There is a subspecialty board for rheumatology certification, offered by the American Board of Internal Medicine, which can provide board certification to approved rheumatologists.
- Pediatric rheumatologists are physicians who specialize in providing comprehensive care to children (as well as their families) with rheumatic diseases, especially arthritis.
- Pediatric rheumatologists are pediatricians who have completed an additional two to three years of specialized training in pediatric rheumatology and are usually board-certified in pediatric rheumatology.
Other doctors who treat arthritis include:
- Pediatricians
- Internists
- General medicine doctors
- Family medicine doctors
- Orthopedic surgeons
What are the treatments and medications for arthritis?
The treatment of arthritis is very dependent on the precise type of arthritis present. An accurate diagnosis increases the chances of successful treatment. Treatments available include:
- Physical therapy
- Home remedies
- Splinting
- Cold-pack application
- Paraffin wax dips
- Anti-inflammatory drugs such as steroids
- Pain medications (ranging from pain-relieving over-the-counter medications such as acetaminophen [Tylenol] and ibuprofen [Motrin, Advil] to narcotics)
- Immune-altering medications
- Biologic medications
- Surgical operations (including joint replacement surgery)
Pain from osteoarthritis of the knee can be relieved by hyaluronic acid injections. Rheumatoid arthritis can require medications that suppress the immune system (disease-modifying medications). Low back arthritis that is irritating the nerves of the spine can require surgical repair. For more on treatments of particular forms of arthritis, see the corresponding articles for the form of arthritis of interest.
What is the prognosis (outlook) for arthritis?
The outlook for patients with arthritis depends on its severity, complications, and whether or not there are non-joint manifestations of the disease.
- For example, rheumatoid arthritis can affect the lungs, kidneys, eyes, etc.
- Chronic joint inflammation can lead to permanent damage to the joint and loss of joint function, making movement difficult or impossible.
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Is it possible to prevent arthritis?
Since most forms of arthritis are inherited to some degree, there is no real way to prevent them. Arthritis that follows joint injury could be prevented by adhering to safety regulations and trying to avoid becoming injured.
Arthritis related to infection (for example, septic arthritis, reactive arthritis, Whipple's disease) could be prevented by not becoming infected with the causative organism. The extent to which this is possible varies depending upon the individual condition.
Is there an arthritis diet?
For most types of arthritis, diets play little or no role in precipitating or exacerbating the condition. However, in general, fish oils have been shown to have anti-inflammatory properties. Some osteoarthritis suffers benefit from omega-3 fatty acid supplements. Some people with osteoarthritis feel they benefit from the curcumin that is present in curry.
Gout is a particular type of metabolic arthritis that is clearly diet-related. Foods that are high in purines, especially red meats and shellfish, can worsen the condition. Moreover, certain foods elevate the levels of uric acid, including alcohol (especially beer) and those foods containing high amounts of fructose (such as the corn syrup found in soft drinks).
For people with celiac disease, gluten-containing foods (wheat, barley, rye) can worsen joint pain.
Are there foods to avoid when you have arthritis?
Which foods make arthritis worse and can trigger arthritis attacks?
With the exception of the unique metabolic form of arthritis in gout and celiac disease, there are no universally accepted foods that must be avoided by people with arthritis. That is, most foods are joint-friendly.
However, certain foods may make arthritis worse by contributing to joint inflammation, weight gain, or both.
The following foods may exacerbate arthritis joint pain and inflammation in some people:
- Processed foods
- Salt
- Red meat
- Alcohol
From 
Arthritis Resources
Senthelal S, Li J, Goyal A, et al. Arthritis. [Updated 2021 Aug 11]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022.
https://www.ncbi.nlm.nih.gov/books/NBK518992/
Arthritis National Research Foundation. Types of Arthritis.
https://curearthritis.org/arthritis-types/
Centers for Disease Control and Prevention. Arthritis Types.
https://www.cdc.gov/arthritis/basics/types.html
Managing Rheumatoid Arthritis With Dietary Interventions:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5682732/
Nutrition Interventions in Rheumatoid Arthritis: The Potential Use of Plant-Based Diets. A Review:
https://www.frontiersin.org/articles/10.3389/fnut.2019.00141/full
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