What is arthritis?

Arthritis is an inflammation of the joints. It is caused by many disorders that affect the joints and their surrounding tissues. Arthritis affects people of all ages, but is more common in people over the age of 65.

Inflammation

A body’s protective immune response to injury or infection. The accumulation of fluid, cells and proteins at the site of an infection or physical injury, resulting in swelling, heat, redness, pain and loss of function.

Joints

A connecting surface or tissue between two bones.

Causes

Causes of arthritis depend on the specific type of arthritis and are detailed under the heading 'Types'.

Risk factors

Some general risk factors for developing arthritis include:

  • Genetics - depending on the underlying cause, there are likely to be genes that increase the risk of arthritis, though exactly how these genes cause arthritis is not well understood;
  • Age - cartilage becomes more brittle and the body less able to repair it as we age. Without functioning cartilage, the joints cannot absorb shock and are more easily damaged;
  • Weight - joint damage is partly caused by the amount of stress placed on joints, which excess weight contributes to, particularly on the hips and knees;
  • Previous injury - joint damage can cause irregularities in the normally smooth joint surface, which can aggravate surrounding tissue;
  • Occupational hazards - jobs that place a high demand on the body, such as factory and construction jobs that require heavy lifting, increase your risk of developing arthritis;
  • Sports - although a sports injury can result in arthritis, it is generally accepted that the benefits of general fitness and muscle strengthening outweigh the risks, and;
  • Illness or infection - an infected joint can develop arthritis from the resulting inflammation.

Cartilage

A tough, flexible connective tissue found in various parts of the body including the joints and larynx.

Genes

A unit of inheritance (heredity) of a living organism. A segment of genetic material, typically DNA, that specifies the structure of a protein or related molecules. Genes are passed on to offspring so that traits are inherited, making you who you are and what you look like.

Genetics

Related to genes, the body's units of inheritance or origin.

Infection

Entry into the body of microorganisms that can reproduce and cause disease.

Inflammation

A body’s protective immune response to injury or infection. The accumulation of fluid, cells and proteins at the site of an infection or physical injury, resulting in swelling, heat, redness, pain and loss of function.

Joints

A connecting surface or tissue between two bones.

Stress

The word ‘stress’ can have a variety of meanings, but generally describes the physical and mental responses of the body to a demand placed upon it. Often used to describe conditions where the demand is high or unable to be resolved and creates anxiety and tension.

Types

There are many types of arthritis. Some of the more common ones are:

Rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic and generally progressive autoimmune disorder causing inflammation of the membranes lining the joints. It typically affects the smaller joints of the hand and feet.

Osteoarthritis

Osteoarthritis (OA) is caused by the degeneration of cartilage, which loses its elasticity and becomes more easily damaged with age. It typically affects weight-bearing joints such as the hips and knees.

The progression of osteoarthritis. 

Juvenile arthritis

Juvenile arthritis is any type of arthritis occurring under the age of 16 years. As young people have not suffered from the same mechanical damage caused by ageing, most cases of arthritis in young people are likely due to autoimmune disorders, although the causes of many cases are unknown.

Infectious (septic) arthritis

Infectious arthritis is a joint infection due to bacteria, viruses or fungi. Usually the infection is established elsewhere in the body and reaches the joints by the bloodstream, or by getting directly into the joint through an open injury.

Polymyalgia rheumatica 

Polymyalgia rheumatica is a type of arthritis that causes inflammation in the larger joints and their surrounding tissues, such as the hips and shoulder joints. It causes muscle pain and stiffness in these areas. It is a common form of arthritis and mainly affects the elderly, but it is treatable. It is not to be confused with fibromyalgia, a different condition in which muscle pain and stiffness can occur anywhere in the body, not just the joints. Fibromyalgia does not cause inflammation. Rather, it is likely the result of overactive pain signals.

Psoriatic arthritis

Psoriatic arthritis is an autoimmune disorder of the joints that can develop if you have psoriasis. While the exact cause is unknown, psoriatic arthritis is associated with HLA-B27, a protein on the surface of white blood cells that is linked to certain autoimmune disorders. If you have psoriatic arthritis, you should take note of what seems to trigger flare-ups, avoid those triggers and ensure you receive ongoing treatment as recommended by your doctor. In about 5% of cases, people develop a more severe form that results in bone deformities.

Gout

Gout is a type of arthritis caused by a build-up of uric acid (urate crystals) in the joints. Men are more likely to get gout, although the risk for women increases after menopause. Gout is one of the few causes of arthritis that can be effectively treated to prevent future damage.

Gout in the toe.Gout. 

Systemic lupus erythematous (SLE)

SLE, more commonly just referred to as lupus, is an autoimmune disorder. Its exact cause is unknown, but could be due to any or a combination of genetics, viruses, stress, or sunlight, among others. Flare-ups, which can vary in duration and severity, are periods when symptoms get worse. Most people with lupus can live a full life, if they stick to their treatment program. In some cases, however, complications can occur that can be life-threatening.

Bursitis

Bursitis is the inflammation of the bursae, which are small fluid-filled sacs between adjoining structures of joints, such as bones, muscles, and tendons. Technically bursitis is not a type of arthritis, because the bursae are outside the joints. It can be caused by injury or underlying conditions, such as rheumatoid arthritis.

Polymyositis

Polymyositis is a disorder of connective tissue that causes inflammation, the cause of which is unknown. It affects women more than men and tends to occur between the ages of 50-70 years, but can affect people of all ages.

Other types of arthritis include:

Autoimmune disorder

A medical condition in which the body's immune system abnormally targets substances that are normally found within the body.

Cartilage

A tough, flexible connective tissue found in various parts of the body including the joints and larynx.

Genetics

Related to genes, the body's units of inheritance or origin.

Inflammation

A body’s protective immune response to injury or infection. The accumulation of fluid, cells and proteins at the site of an infection or physical injury, resulting in swelling, heat, redness, pain and loss of function.

Joints

A connecting surface or tissue between two bones.

Scleroderma

A rare condition in which excess collagen fibres are produced by the body, affecting the skin and internal organs.

Stress

The word ‘stress’ can have a variety of meanings, but generally describes the physical and mental responses of the body to a demand placed upon it. Often used to describe conditions where the demand is high or unable to be resolved and creates anxiety and tension.

Tendons

Dense bands of connective tissue that attach muscles to bones.

Viruses

A microscopic infectious agent that replicates itself only within cells of living hosts; a piece of nucleic acid (DNA or RNA) wrapped in a protein coat.

Membranes

A thin layer of tissue that lines the surfaces of organs or cells.

Reiter's syndrome

An autoimmune condition marked by painful and swollen joints, pain during urination and eye redness.

Tendinitis

An inflammation of a tendon, either from overuse, infection or rheumatic disease.

Signs and symptoms

Symptoms vary according to the cause of arthritis. Common symptoms include:

  • Joint stiffness, swelling and pain;
  • A skin rash around affected joints;
  • Muscle weakness and wasting;
  • Fever;
  • Fatigue;
  • Weight loss, and;
  • Restlessness and anxiety.

Anxiety

A feeling of tension, nervousness and dread about future events. It can trigger physical symptoms such as a rapid pulse or breathing difficulties.

Fatigue

A state of exhaustion and weakness.

Fever

An increase in body temperature above the normal temperature range. Fever is often caused by the body's immune reaction to infection.

Joint

A connecting surface or tissue between two bones.

Methods for diagnosis

Methods used to diagnose arthritis are:

Physical examination

Your doctor will likely look for signs of:

  • Joint swelling, stiffness or tenderness;
  • Redness or warmth around the joint due to inflammation;
  • Restricted movement, and;
  • Bumps or nodules.

Laboratory tests

Erythrocyte sedimentation rate (ESR)

ESR is a test used to indicate inflammation, but it does not diagnose a specific disorder. For this test a blood sample is taken and the rate at which red blood cells accumulate at the bottom of a test tube is measured. The higher the rate, the greater the degree of inflammation. Normal values will vary between laboratories according to different methods used. Your doctor will tell you what your results mean.

C-reactive protein (CRP)

Measuring CRP levels in the blood provides an indication of the degree of inflammation in the body. CRP is a general test that indicates that there is inflammation somewhere in the body, but does not localise the inflammation or identify its underlying cause. Your doctor may order this test to check if anti-inflammatory medicine is working, or during any flare-up periods of the inflammatory diseases.

Anti-cyclic citrullinated peptide (CCP) antibody

Anti-CCP antibodies are auto-antibodies, which means they are mistakenly directed against a person's healthy tissues instead of microorganisms. This test is used to confirm a diagnosis of rheumatoid arthritis.

Rheumatoid factor (RF)

RF is an auto-antibody directed against one of the body's antibodies, called immunoglobulin G (IgG). RF binds to IgG, forming immune complexes. When these complexes are deposited in the joints, they produce a reaction that causes inflammation. Up to 70% of people with rheumatoid arthritis have RF in their blood, but some people without rheumatoid arthritis can have it too.

Antinuclear antibody (ANA)

Normally the immune system produces antibodies to fight infection. ANAs attack your body's own cells. A positive result for ANAs does not necessarily mean you have an autoimmune disorder, because it can be caused by other conditions or certain medications. Some healthy people also have ANAs and this increases with age.

Human leucocyte antigen (HLA) B27 typing

HLAs are found on the surface of white blood cells. A particular type, HLA-B27, is associated with certain autoimmune disorders that may cause arthritis. In a healthy person, HLA-B27 will generally be absent, but its presence in your blood does not necessarily mean you have an autoimmune condition.

Other laboratory tests:

Other diagnostic tests:

Antibodies

A protein molecule produced by the immune system. Antibodies bind specifically to foreign substances to neutralise them or target them for destruction.

Autoimmune disorder

A medical condition in which the body's immune system abnormally targets substances that are normally found within the body.

Biopsy

The removal of a tissue sample for microscopic laboratory examination. It is used to determine the presence, cause and type of the disease.

Creatinine

A chemical waste product of protein metabolism that is filtered from the blood by the kidneys.

Computerised tomography

A scan that uses X-rays to create a 3D image of the body. This can detect abnormalities more effectively than a simple X-ray can.

HLA-B27

A type of antigen associated with particular inflammatory diseases.

Immune system

The organs and cells involved in protecting the body against infection.

Infection

Entry into the body of microorganisms that can reproduce and cause disease.

Inflammation

A body’s protective immune response to injury or infection. The accumulation of fluid, cells and proteins at the site of an infection or physical injury, resulting in swelling, heat, redness, pain and loss of function.

Joint

A connecting surface or tissue between two bones.

Magnetic resonance imaging

A type of imaging that uses a magnetic field and low-energy radio waves, instead of X-rays, to obtain images of organs.

Nodules

A small growth or lump of tissue.

Red blood cells

Cells in the blood that transport oxygen from the lungs throughout the body and carbon dioxide from the body to the lungs.

Ultrasound

A scan that uses high-frequency soundwaves to produce images of the body’s internal structures.

Uric acid

A chemical that is a by-product of the digestion of proteins. It is filtered from the blood and excreted from the body as part of the urine.

White blood cells

Cells of the immune system that participate in immune and inflammatory reactions.

X-ray

A scan that uses ionising radiation beams to create an image of the body’s internal structures.

Immunoglobulin G

A type of antibody produced by the body in response to an infection by bacteria, viruses or fungi, to protect the body in the future from the same infection.

Lyme disease

An infection caused by Borrelia bacteria that is spread through a tick bite. It may cause a characteristic rash and/or non-specific symptoms that mimic other conditions.

Serological

Refers to the immunological properties in the clear component of the blood (i.e. serum), once all the blood cells and clotting factors are removed.

Types of treatment

Treatment options your doctor will consider include:

Medications

Pain-relief medications

These medications reduce pain and some are available without a prescription, such as paracetamol and low-dose codeine. Some that require a prescription include oxycodone, propoxyphene and higher-dose codeine.

Non-steroidal anti-inflammatory drugs (NSAIDs)

NSAIDs are a group of medications that reduce inflammation, pain and fever. As such, they are used to ease these symptoms in a wide range of conditions. Examples are ibuprofen and naproxen.

Disease modifying anti-rheumatic drugs (DMARDs)

DMARDs are a range of drugs that act on the immune system in different ways to prevent inflammation. They include drugs such as methotrexate, sulfasalazine and hydroxychloroquine. Their effects are not immediate and can take weeks to months to be noticed. Unlike NSAIDs, early intervention with DMARDs can slow down disease progression.

Biological therapies

Biological therapies can work faster than DMARDs. They are drugs that act on the immune system and are sometimes used in conjunction with other medication if you have rheumatoid arthritis.

Corticosteroids

These are powerful anti-inflammatories that block the inflammatory pathway of the immune response. They can be taken orally or injected. Injection is usually only required in extreme cases of inflammation that only affect one or two joints.

Physiotherapy

Physiotherapy can help by improving mobility, flexibility and strength in arthritic joints.

Surgery

When non-surgical methods fail, an orthopaedic surgeon may perform surgery to:

  • Remove diseased or damaged tissue;
  • Realign the joints;
  • Release or repair tendons;
  • Remove bone;
  • Release trapped nerves;
  • Fuse the ends of joint bones together to reduce joint motion and relieve pain, and;
  • Replace a damaged joint with an artificial one.

Lifestyle

Exercise

Regular exercise can help improve flexibility, improve supporting-muscle strength and reduce fatigue.

Assistive devices

Assistive devices, such as walkers, canes and raised toilet seats, are available to help protect the joints and improve your ability to perform daily tasks.

Hot and cold packs

Applying icepacks or heating pads may help reduce pain. However, speak to your doctor first, as this can make some types of arthritis worse.

Other therapies

Unproven therapies for arthritis include oral glucosamine and chondroitin, and acupuncture.

Acupuncture

A form of complementary therapy that involves fine sterilised needles being inserted into the skin at specific points to treat medical conditions.

Fatigue

A state of exhaustion and weakness.

Fever

An increase in body temperature above the normal temperature range. Fever is often caused by the body's immune reaction to infection.

Glucosamine

A naturally-occurring substance found in connective tissues such as cartilage.

Immune system

The organs and cells involved in protecting the body against infection.

Inflammation

A body’s protective immune response to injury or infection. The accumulation of fluid, cells and proteins at the site of an infection or physical injury, resulting in swelling, heat, redness, pain and loss of function.

Joints

A connecting surface or tissue between two bones.

Nerves

One or more fibres that transmit signals of sensation and motion between the brain or spinal cord and other parts of the body.

NSAIDs

Non-steroidal anti-inflammatory drugs are commonly used to manage arthritis-related pain and inflammation and other musculoskeletal disorders. NSAIDs include aspirin and ibuprofen.

Orthopaedic

The medical specialty that look at deformities and diseases of the bones.

Physiotherapy

A healthcare profession that treats bodily weaknesses or defects with physical remedies, such as massage or exercise.

Tendons

Dense bands of connective tissue that attach muscles to bones.

Potential complications

Medications

Non-steroidal anti-inflammatory drugs (NSAIDs)

Side effects associated with long-term use of NSAIDs can be gastritis and ulcers in the digestive system. NSAIDs can also interact with other drugs. If you are taking NSAIDs for arthritis, your doctor or pharmacist will tell you what drugs you should not mix with them. 

DMARDS

DMARDs can have a wide range of side effects depending on the agent used. Methotrexate can weaken the immune system, resulting in increased susceptibility to infection. It can also cause damage to the lungs and liver. Side effects and potential complications will be closely monitored by your treating doctor. 

Biological therapies

Biological therapies can result in the formation of anti-drug antibodies (ADAs), which can reduce the effectiveness of a treatment. Further research is needed to identify the optimal dosage required to reduce the problem of ADA formation. Biological therapies can also weaken the immune system, making it harder for the body to fight infections.

Corticosteroids

Side effects of long-term oral or intravenous corticosteroids, include osteoporosis, a weakened immune system, weight gain, glaucoma, muscle weakness and elevated blood pressure.

Antibodies

A protein molecule produced by the immune system. Antibodies bind specifically to foreign substances to neutralise them or target them for destruction.

Blood pressure

The pressure the blood places on the walls of the arteries, largely mirroring the contraction of the heart, and consisting of two readings. The higher reading is systolic blood pressure, when the heart contracts, and the lower is diastolic blood pressure, when the heart is relaxed.

Digestive system

The series of organs within the body that contribute to the digestion of food. It begins at the mouth and ends at the anus, and includes the stomach, small and large intestines as well as the pancreas, gallbladder and liver.

Glaucoma

A condition in which there is increased pressure in the eyeball, gradually resulting in loss of sight.

Immune system

The organs and cells involved in protecting the body against infection.

Infection

Entry into the body of microorganisms that can reproduce and cause disease.

NSAIDs

Non-steroidal anti-inflammatory drugs are commonly used to manage arthritis-related pain and inflammation and other musculoskeletal disorders. NSAIDs include aspirin and ibuprofen.

Osteoporosis

A condition in which bone loses mass and density and becomes weak, brittle and prone to fracture. Osteoporosis is often the result of a deficiency of calcium or vitamin D, or hormonal changes.

Ulcers

An open sore in the skin or mucous membranes such as those of the stomach lining, intestine or mouth.

Prognosis

The outlook for arthritis varies, according to the underlying cause and response to treatment. Most forms of arthritis are chronic, with only a few able to be cured with treatment. Early diagnosis generally results in better treatment outcomes.

Prevention

Ways you can help prevent the development of arthritis include:

  • Regular exercise and maintaining a healthy weight;
  • Avoiding high-impact sports if you suffer from arthritis;
  • Quitting smoking, because it can impair the healing of tissues, and;
  • Taking breaks from work and getting enough sleep.