Arthritis is a general term for more than 100 conditions that cause pain, swelling and stiffness in the joints.[1][2] Osteoarthritis (OA) is the most common type.[1][2] Rheumatoid arthritis is an autoimmune disease, gout comes from too much uric acid in the blood, and an infection inside a joint (septic arthritis) needs urgent medical help.[7][11][10]
- What is arthritis?
- What are the symptoms of arthritis?
- What is osteoarthritis?
- What does severe arthritis mean?
- What are rheumatoid arthritis and psoriatic arthritis?
- What is septic arthritis?
- What is gout?
- How is arthritis diagnosed?
- How is arthritis treated?
- Frequently asked questions
- When is urgent help needed?
- What should I do next?
What is arthritis?
Arthritis is a condition that causes pain, swelling and stiffness in one or more joints, and it can make moving the affected joints difficult.[1] You can get arthritis in any joint.[1] Joints commonly affected include those in the wrists, hands and fingers, the ankles, feet and toes, and the knees and hips.[1] In the United States, an estimated 53.2 million adults (21.2%) had diagnosed arthritis in 2019 to 2021, and arthritis is a leading cause of activity limitations, disability and chronic pain.[3]
| Type | How it can affect you |
|---|---|
| Osteoarthritis | Often affects weight-bearing joints, such as the knees and feet. It is the most common type of arthritis and usually starts in the late 40s.[1] |
| Rheumatoid arthritis | Usually first felt in the small joints of the hands and feet. It is often diagnosed between the ages of 40 and 60.[1] |
| Psoriatic arthritis | Joint pain, swelling and stiffness, sometimes with a red, scaly rash called psoriasis.[1] |
| Gout | Often affects the big toe joint, which can be painful, swollen and hot. The chance of getting gout increases with age.[1] |
| Septic arthritis | An infection in a joint. It usually affects one large joint, such as the hip or knee.[10] |
Do not self-diagnose. See a doctor if you are worried.[1]
What are the symptoms of arthritis?
Arthritis causes pain, swelling and stiffness in the joints, which can make moving the joint difficult.[1] Symptoms may sometimes suddenly get worse. This is known as a flare-up, and it can last several days.[1]
Some people with rheumatoid arthritis also have problems in other parts of the body, including inflammation of areas such as the lungs, heart and eyes.[7]
What is osteoarthritis?
OA is the most common type of arthritis, and it most often causes problems in the knees, hips and small joints of the hands.[4] Among US adults with arthritis, OA is the most common subtype, at 49.6% (33.2 million people).[2] In OA, the protective cartilage on the ends of the bones breaks down, causing pain, swelling and problems moving the joint.[4] Guidelines describe OA as a disease of the whole joint, with changes in the cartilage, the bone and the joint lining.[5]
Mild symptoms can sometimes be managed with simple measures, including regular exercise, losing weight if you are overweight, wearing suitable footwear and using special devices to reduce the strain on your joints during everyday activities.[4] NICE (the UK’s National Institute for Health and Care Excellence) names therapeutic exercise and weight management, if appropriate, along with information and support, as the core treatments for OA.[6]
More on what raises the risk of OA
The exact cause of OA is not known, but several things are thought to increase the risk.[4]
- Joint injury: overusing a joint that has not had enough time to heal after an injury or operation.[4]
- Other conditions: OA can happen in joints severely damaged by a previous or existing condition, such as rheumatoid arthritis or gout.[4]
- Age: the risk increases as you get older.[4]
- Family history: OA may run in families, although studies have not identified a single gene responsible.[4]
- Obesity: being obese puts excess strain on the joints, particularly those that bear most of your weight, such as the knees and hips.[4]
- Sex: OA is more common in women than in men.[4]
Read more about how to manage arthritis pain, and about hip osteoarthritis.
What does severe arthritis mean?
The severity of OA symptoms varies greatly from person to person, and between different affected joints.[4] For some people, symptoms are mild and may come and go. Others have more continuous and severe problems that make everyday activities difficult.[4] If symptoms are severe, treatments such as painkillers and a structured exercise plan with a physiotherapist may be needed.[4]
NICE advises considering referral for joint replacement for people with hip, knee or shoulder OA if their joint symptoms (such as pain, stiffness, reduced function or progressive joint deformity) are substantially impacting their quality of life and non-surgical management (for example, therapeutic exercise, weight loss, pain relief) is ineffective or unsuitable.[6] Read about total knee replacement.
What are rheumatoid arthritis and psoriatic arthritis?
Rheumatoid arthritis is an autoimmune disease. The immune system, which usually fights infection, attacks the cells that line the joints by mistake, making the joints swollen, stiff and painful.[7] Over time, this can damage the joints, cartilage and nearby bone.[7]
- It is not clear what triggers the problem with the immune system, but the risk is increased in women, in people with a family history of rheumatoid arthritis, and in people who smoke.[7]
- Rheumatoid arthritis is caused in many cases by the interaction between genes and environmental factors, including tobacco.[8]
- Diagnosing rheumatoid arthritis quickly is important, because early treatment can prevent it getting worse and reduce the risk of joint damage.[7]
- Early treatment with disease-modifying anti-rheumatic drugs (DMARDs) is the standard of care.[8]
- Early diagnosis and appropriate treatment enable many people to have periods of months or even years between flares.[7]
- Psoriatic arthritis is a long-term condition that causes joint pain, swelling and stiffness, and medicines are the main treatment.[9]
What is septic arthritis?
Septic arthritis is joint inflammation caused by an infection.[10] The infection is usually bacterial, and occasionally fungal, mycobacterial, viral or due to other uncommon pathogens (germs).[10] It usually affects one large joint, such as the hip or knee.[10] Although uncommon, septic arthritis is an orthopaedic emergency that can cause significant joint damage, and early diagnosis and treatment are crucial for preserving joint function.[10]
What is gout?
Gout is a type of arthritis that causes sudden, severe joint pain, usually in the big toe but sometimes in other joints in the feet, ankles, hands, wrists, elbows or knees.[11] The skin over the affected joint becomes hot, swollen and red.[11] Gout is caused by having too much uric acid in the blood. This can lead to crystals forming around the joints, which causes pain.[11]
- An attack of gout usually lasts 1 to 2 weeks if left untreated, and leaving gout untreated may cause lasting damage to joints.[11]
- Attacks of gout are usually treated with a non-steroidal anti-inflammatory drug (NSAID), such as ibuprofen.[11]
- People with frequent attacks or high levels of uric acid in the blood may need to take uric acid-lowering medicine.[11]
- See a doctor if you have symptoms of gout for the first time.[11]
How is arthritis diagnosed?
A healthcare professional will ask about your symptoms and medical history and check your joints.[1] Tests can include blood tests, an X-ray or ultrasound scan, and a sample of fluid taken from a joint using a thin needle, which helps to confirm gout.[1] You may be referred to a specialist called a rheumatologist if the doctor thinks you might have rheumatoid arthritis or gout.[1]
For OA, NICE advises diagnosing it clinically, without imaging, in people who are 45 or over with activity-related joint pain and either no morning joint-related stiffness or morning stiffness that lasts no longer than 30 minutes.[6]
How is arthritis treated?
Treatment depends on the type of arthritis you have and how it is affecting you.[1] Treatments include physiotherapy to improve strength and mobility, occupational therapy to help with everyday tasks, medicines to relieve symptoms or to reduce the activity of the immune system, and equipment such as walking aids.[1] Surgery is an option if symptoms are severe and other treatments have not helped.[1]
Frequently asked questions
What is the most common type of arthritis?
OA is the most common type of arthritis.[1] Among US adults with arthritis, 49.6% have OA and 15.8% have rheumatoid arthritis.[2]
Is gout a type of arthritis?
Yes. Gout is a type of arthritis that causes sudden, severe joint pain.[11]
Does arthritis only affect older people?
No. OA usually starts in the late 40s, and rheumatoid arthritis is often diagnosed between the ages of 40 and 60.[1] Juvenile idiopathic arthritis affects children under the age of 16.[1]
When is urgent help needed?
The list below covers the signs that should not wait for a routine appointment.
What should I do next?
For anyone with persistent joint pain, swelling or stiffness, or who is unsure which type of arthritis they have, an assessment is a sensible next step. It brings together the patient’s story, an examination and any tests that help. It looks at the structure involved, the patient as a whole person and the goal they want to return to. An appointment supports an informed decision. It is not a commitment to surgery.
- Read about how to manage arthritis pain and about weight loss and knee osteoarthritis.
- Arrange a knee assessment when you are ready.
- Browse the Knee Hub for other knee problems, or more articles.
- Read more about Dr Sean Leo, who is named as the author of this page.
This page provides general information and cannot diagnose an individual condition. OrthoKinetics does not provide emergency or urgent care through this webpage or its WhatsApp contact.
References
- NHS. Arthritis. https://www.nhs.uk/conditions/arthritis/
- Foster AL, Boring MA, Lites TD, Croft JE, Odom EL, Fallon EA. Distribution of Arthritis Subtypes Among Adults With Arthritis in the United States, 2017-March 2020. Prev Chronic Dis. 2025;22:E28. doi:10.5888/pcd22.240393. PMID:40539903.
- Fallon EA, Boring MA, Foster AL, Stowe EW, Lites TD, Odom EL, Seth P. Prevalence of Diagnosed Arthritis – United States, 2019-2021. MMWR Morb Mortal Wkly Rep. 2023;72(41):1101-1107. doi:10.15585/mmwr.mm7241a1. PMID:37824422. PMCID:PMC10578950.
- NHS. Osteoarthritis. https://www.nhs.uk/conditions/osteoarthritis/
- Kolasinski SL, Neogi T, Hochberg MC, et al. 2019 American College of Rheumatology/Arthritis Foundation Guideline for the Management of Osteoarthritis of the Hand, Hip, and Knee. Arthritis Care Res (Hoboken). 2020;72(2):149-162. doi:10.1002/acr.24131. PMCID:PMC11488261.
- NICE. Osteoarthritis in over 16s: diagnosis and management. NICE guideline NG226. 2022. https://www.nice.org.uk/guidance/ng226
- NHS. Rheumatoid arthritis. https://www.nhs.uk/conditions/rheumatoid-arthritis/
- Chauhan K, Jandu JS, Brent LH, Al-Dhahir MA. Rheumatoid Arthritis. In: StatPearls. Treasure Island (FL): StatPearls Publishing; 2023. PMID:28723028. https://www.ncbi.nlm.nih.gov/books/NBK441999/
- NHS. Psoriatic arthritis. https://www.nhs.uk/conditions/psoriatic-arthritis/
- Momodu II, Savaliya V. Septic Arthritis. In: StatPearls. Treasure Island (FL): StatPearls Publishing; 2023. PMID:30844203. https://www.ncbi.nlm.nih.gov/books/NBK538176/
- NHS. Gout. https://www.nhs.uk/conditions/gout/
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