There are over 100 forms of arthritis and other rheumatic diseases. These diseases may cause pain, stiffness, and swelling in joints and other supporting structures of the body such as muscles, tendons, ligaments, and bones. Some forms can also affect other parts of the body, including various internal organs.

Many people use the word "arthritis" to refer to all rheumatic diseases. However, the word literally means joint inflammation; that is, swelling, redness, heat, and pain caused by tissue injury or disease in the joint. The many different kinds of arthritis comprise just a portion of the rheumatic diseases. Some rheumatic diseases are described as connective tissue diseases because they affect the body's connective tissue--the supporting framework of the body and its internal organs. Others are known as autoimmune diseases because they are caused by a problem in which the immune system harms the body's own healthy tissues.

Juvenile Rheumatoid Arthritis

Arthritis means "joint inflammation" and refers to a group of diseases that cause pain, swelling, stiffness, and loss of motion in the joints. "Arthritis" is often used as a more general term to refer to the more than 100 rheumatic diseases that may affect the joints but can also cause pain, swelling, and stiffness in other supporting structures of the body such as muscles, tendons, ligaments, and bones. Some rheumatic diseases can affect other parts of the body, including various internal organs. Children can develop almost all types of arthritis that affect adults, but the most common type that affects children is juvenile rheumatoid arthritis (JRA).

JRA is an autoimmune disorder, which means that the body mistakenly identifies some of its own cells and tissues as foreign. The immune system, which normally helps to fight off harmful, foreign substances such as bacteria or viruses, begins to attack healthy cells and tissues. The result is inflammation--marked by redness, heat, pain, and swelling. Doctors do not know why the immune system goes awry in children who develop JRA. Scientists suspect that it is a two-step process. First, something in a child's genetic makeup gives them a tendency to develop JRA; then an environmental factor, such as a virus, triggers the development of JRA.

The most common symptom of all types of JRA is persistent joint swelling, pain, and stiffness that typically is worse in the morning or after a nap. The pain may limit movement of the affected joint although many children, especially younger ones, will not complain of pain. JRA commonly affects the knees and joints in the hands and feet. One of the earliest signs of JRA may be limping in the morning because of an affected knee. Besides joint symptoms, children with systemic JRA have a high fever and a light skin rash. The rash and fever may appear and disappear very quickly. Systemic JRA also may cause the lymph nodes located in the neck and other parts of the body to swell. In some cases (less than half), internal organs including the heart and, very rarely, the lungs may be involved.

Eye inflammation is a potentially severe complication that sometimes occurs in children with pauciarticular JRA. Eye diseases such as iritis and uveitis often are not present until some time after a child first develops JRA.

Typically, there are periods when the symptoms of JRA are better or disappear (remissions) and times when symptoms are worse (flare-ups). JRA is different in each child--some may have just one or two flare-ups and never have symptoms again, while others experience many flare-ups or even have symptoms that never go away.

Some children with JRA may have growth problems. Depending on the severity of the disease and the joints involved, growth in affected joints may be too fast or too slow, causing one leg or arm to be longer than the other. Overall growth may also be slowed. Doctors are exploring the use of growth hormones to treat this problem. JRA also may cause joints to grow unevenly or to one side.

Doctors usually suspect JRA, along with several other possible conditions, when they see children with persistent joint pain or swelling, unexplained skin rashes and fever, or swelling of lymph nodes or inflammation of internal organs. A diagnosis of JRA also is considered in children with an unexplained limp or excessive clumsiness.

Juvenile rheumatoid arthritis is arthritis that causes joint inflammation and stiffness for more than 6 weeks in a child of 16 years of age or less. Inflammation causes redness, swelling, warmth, and soreness in the joints, although many children with JRA do not complain of joint pain. Any joint can be affected and inflammation may limit the mobility of affected joints. One type of JRA can also affect the internal organs. Doctors classify JRA into three types by the number of joints involved, the symptoms, and the presence or absence of certain antibodies found by a blood test. (Antibodies are special proteins made by the immune system.) These classifications help the doctor determine how the disease will progress and whether the internal organs or skin is affected.

Pauciarticular Juvenile Rheumatoid Arthritis

Pauciarticular means that four or fewer joints are affected. Pauciarticular is the most common form of JRA; about half of all children with JRA have this type. Pauciarticular disease typically affects large joints, such as the knees. Girls under age 8 are most likely to develop this type of JRA.

Some children have special kinds of antibodies in the blood. One is called antinuclear antibody (ANA) and one is called rheumatoid factor. Eye disease affects about 20 to 30 percent of children with pauciarticular JRA. Up to 80 percent of those with eye disease also test positive for ANA and the disease tends to develop at a particularly early age in these children. Regular examinations by an ophthalmologist (a doctor who specializes in eye diseases) are necessary to prevent serious eye problems such as iritis (inflammation of the iris, the colored part of the eye) or uveitis (inflammation of the uvea, or the inner eye). Some children with pauciarticular disease outgrow arthritis by adulthood, although eye problems can continue and joint symptoms may recur in some people.

Polyarticular Juvenile Rheumatoid Arthritis

About 30 percent of all children with JRA have polyarticular disease. In polyarticular disease, five or more joints are affected. The small joints, such as those in the hands and feet, are most commonly involved, but the disease may also affect large joints. Polyarticular JRA often is symmetrical; that is, it affects the same joint on both sides of the body. Some children with polyarticular disease have an antibody in their blood called IgM rheumatoid factor (RF). These children often have a more severe form of the disease, which doctors consider to be similar in many ways to adult rheumatoid arthritis.

Systemic Juvenile Rheumatoid Arthritis

Besides joint swelling, the systemic form of JRA is characterized by fever and a light skin rash, and may also affect internal organs such as the heart, liver, spleen, and lymph nodes. Doctors sometimes call it Still's disease. Almost all children with this type of JRA test negative for both RF and ANA. The systemic form affects 20 percent of all children with JRA. A small percentage of these children develop arthritis in many joints and can have severe arthritis that continues into adulthood.

Other Forms of Arthritis (in alphabetical order)

-Ankylosing spondylitis (AS)

A chronic inflammatory form of arthritis that affects the spinal joints. The hallmark feature of AS is the involvement of the joints at the base of the spine where the spine joins the pelvis - the sacroiliac (SI) joints.

-Carpal tunnel syndrome

Carpal tunnel syndrome is a condition in which the median (pronounced mee-dee-an) nerve becomes compressed. The median nerve is the nerve that travels down the arm into the hand. With carpal tunnel syndrome the nerve is squeezed as it passes through the narrow path (or tunnel) at the wrist. The pressure on the wrist can cause the fingers and thumb to feel tingly and numb. They may feel paralysed, or unable to move.

-Diffuse Idiopathic Skeletal Hyperostosis-DISH (sometimes called Forestier’s disease)

This disorder is considered a form of degenerative arthritis and is characterized by excessive bone growth along the sides of the vertebrae of the spine. It is also associated with inflammation and calcification (bone growth) at other areas of the body where tendons and ligaments attach to bone, such as at the elbow, knee and the heel of the foot. These can lead to bone spurs. Heel spurs, for example, are common among people with DISH.


Fibromyalgia (pronounced fy-bro-my-al-ja) is widespread pain in the muscles, ligaments and tendons.  Ligaments and tendons connect muscles to bones. Fibromyalgia also causes people to have trouble sleeping and feel very tired all the time.


Gout is a type of arthritis that results from too much uric (pronounced yur-ik) acid in the body. Uric acid is a waste product that naturally occurs in the body. It is normally flushed from the body by the kidneys through urine. With gout the body either makes too much uric acid or does not excrete enough. The uric acid forms into crystals that, because these have nowhere else to go, deposit in different parts of the body. Often the excess uric acid crystals deposit in the joints. This causes pain, swelling and tenderness in the area. This is called inflammation. Gout most often affects the big toe but can also affect the ankle, knee, foot, hand, wrist and elbow.

-Infectious arthritis

Infectious arthritis is a form of joint inflammation caused by a germ. The germ can be a bacterium, a virus or a fungus. Infection of the joints usually occurs after a previous infection elsewhere in the body. There is usually only one joint involved, though sometimes two or three joints can become infected. Mostly, infectious arthritis affects the large joints (shoulders, hips, knees), but smaller joints (fingers, ankles) can also be involved.


Lupus is the name given to a group of chronic autoimmune diseases. Systemic lupus erythematosus (SLE) is the most common and serious type of lupus. With SLE, the immune system that normally protects the body from germs, viruses, and bacteria begins to malfunction. It generates antibodies that attack healthy tissue in different parts of the body. These tissues become inflamed as a result. Inflammation can occur in the skin, muscles, joints, heart, lungs, kidneys, blood vessels and the nervous system. SLE can fluctuate between active periods (flare-ups or exacerbation), and times of minimal symptoms or no symptoms (remission).

Other types of lupus are discoid lupus erythematosus (DLE) and subacute cutaneous lupus (SCLE). With these types of lupus, skin rashes and sun sensitivity are the main symptoms, and the internal organs are not attacked. However, approximately 10% of people diagnosed with these more limited forms of lupus will go on to develop symptoms of SLE.

-Lyme disease

Lyme disease is an inflammatory disorder begun by receiving a bite from a tick that is infected by a bacterium.  The bacterium enters the body at the spot of the tick bite, and begins to multiply and travel to different parts of the body.  If untreated, it can progress to produce an infection that can take a variety of forms, but usually involves chronic inflammation affecting joints, the nervous system, the heart and the skin. More on Lyme Disease

-Osteoarthritis (OA)

Osteoarthritis (OA) is often called 'wear and tear' of the joints.  OA causes certain parts of the joints to weaken and break down. Cartilage, the tough elastic material that cushions the ends of the bones, begins to crack and get holes in it. Bits of cartilage can break off into the joint space and irritate soft tissues, such as muscles, and cause problems with movement. Much of the pain of OA is a result of muscles and the other tissues that help joints move (such as tendons and ligaments) being forced to work in ways for which they were not designed, as a result of damage to the cartilage. Cartilage itself does not have nerve cells, and therefore cannot sense pain, but the muscles, tendons, ligaments and bones do. After many years of cartilage erosion, bones may actually rub together. This grinding of bone against bone adds further to the pain. Bones can also thicken and form growths, called spurs or osteophytes, which rub together.  Also, when cartilage is weak or damaged, the surrounding bones place extra force on it, and this may cause excessive blood flow (hyperemia) that can cause pain, especially at night.


"Osteo' means bone, and "porosis" thinning or becoming more porous, so osteoporosis literally means "thinning of bone." It is commonly confused with the word osteoarthritis, which is a form of arthritis that results in breakdown of the cartilage covering the ends of bones. In contrast, osteoporosis is a condition where bone itself breaks down.  Bones then become thin, brittle and easily broken. For example, sneezing can cause a person's rib to break or stumbling can lead to fracture of one of the bones in the spine.

The bones most commonly affected by osteoporosis are those in the hip, wrist and back (the vertebrae - pronounced ver-te-bray), particularly those in the mid-back.  As vertebrae become thin, they are prone to collapse from relatively minor forces. Usually the fronts of the vertebrae break, leading to a state called wedging, which causes a person to stoop forward and develop a hump-like deformity on the upper spine. Those people who do not develop wedging may notice a progressive loss of height as bone collapse occurs.

-Paget’s disease

Paget’s disease causes a malfunction in the normal process of bone remodelling. Normally, bone is continually breaking down and rebuilding. This usually slow process of bone destruction and growth is somehow altered in Paget's disease. When an area of bone is destroyed in a person with Paget’s disease, the bone that replaces it is soft and porous. Soft bone can be weak and easily bend, leading to shortening of the affected part of the body.  The bone replacement also takes place very quickly and excess bone may be formed. This can cause the bone to get larger, be painful and break easily.

-Polymyalgia rheumatica

Polymyalgia rheumatica is a syndrome characterized by severe pain and stiffness in the muscles of the neck, shoulder girdles, low back, hips and thighs.  There is no corresponding weakness of the muscles. It is thought that polymyalgia rheumatica is a result of blood vessels becoming inflamed. The name polymyalgia rheumatica actually comes from Greek words.  In Greek, 'poly' means 'many,' 'my' means 'muscle,' and 'algia' means 'pain' (many muscle pain) and 'rheumatica' refers to 'muscle and soft tissue.' A condition associated with polymyalgia rheumatica is called giant cell arteritis.  It sometimes occurs in people who have polymyalgia rheumatica.  It causes the arteries on the upper front side of the head, called the temporal arteries, to narrow.  The arteries can become blocked and this can result in loss of vision.


Polymyositis (pronounced pah-lee-my-o-site-iss) is a disease that causes muscles to be weak.  After a person has had polymyositis for a long time his or her muscles can get smaller. Polymyositis can affect the muscles in any part of the body.  It can also affect the lungs and the heart. It is called dermatomyositis (pronounced der-ma-toe-my-o-site-iss) when the skin is also affected.  It can cause skin rashes all over the body. Both polymyositis and dermatomyositis are chronic diseases.  This means that they can last a very long time. With both forms of the disease, there may be times when the symptoms are stronger (active periods) and then periods when the symptoms lessen (remissions).


Pseudogout results from a build up of calcium crystals (calcium pyrophosphate dihydrate) in a joint.  The joint reacts to the calcium crystals by becoming inflamed. The calcium deposits and chronic inflammation can cause parts of the joint structure to weaken and break down. Cartilage, the tough elastic material that cushions the ends of the bones, can begin to crack and get holes in it. Bits of cartilage may break off into the joint space and irritate soft tissues, such as muscles, and cause problems with movement.

-Psoriatic arthritis

Psoriatic arthritis is a long-lasting condition that causes skin rashes and produces joint inflammation. Over 80% of people with psoriatic arthritis also have involvement of the finger and toenails. The pattern of joint involvement varies widely in people with psoriatic arthritis, though it can affect the wrists, knees, ankles, finger and toe joints, the spine, and the sacroiliac joints (joints in the lower back where the spine connects with the hips). Psoriatic arthritis is linked to psoriasis, a disorder causing areas of the skin to become inflamed and be covered with silvery or grey scales. Psoriasis can also cause the nails on the hands and feet to develop small holes and to lift.

-Raynaud's phenomenon

Raynaud's phenomenon is a condition resulting from poor circulation in the extremities (i.e., fingers and toes).  In a person with Raynaud's phenomenon, when his or her skin is exposed to cold or the person becomes emotionally upset, the blood vessels under the skin tighten and the blood flow slows. This is called vasospasm. Hands and feet have fewer large blood vessels and, therefore, when a vasospasm occurs, it is harder for the blood to keep flowing and these areas may turn blue because less oxygen is reaching the skin. The skin will also feel cold because less blood is reaching the skin to keep it warm.  While attacks of vasospasm may last from minutes to hours, only rarely do they cause severe tissue damage.

-Reactive arthritis

Reactive arthritis refers to pain, stiffness, redness or swelling in a joint resulting from a previous infection. It most often occurs in the joints of the lower limbs (knees, ankles, toes), but can also occur in the upper limbs.  Problems may be in the joints only or involve other body systems such as the eyes, skin muscles or tendons.

-Reiter's syndrome

Reiter's syndrome is a subtype of reactive arthritis.  Reactive arthritis is inflammation of the joints caused by certain bacterial infections. The arthritis occurs after a person has experienced a bacterial infection, and the bacteria travel through the body to a joint or joints. The person may have already been treated for the initial infection, and there may be a delay of weeks before the symptoms of reactive arthritis show themselves.  Reiter's syndrome is said to occur when reactive arthritis is evident and at least one other non-joint area, such as the eyes, skin or muscles, is affected.

-Repetitive Stress Injury

The term repetitive stress injury, or repetitive strain, refers to a group of conditions caused by placing too much stress on a joint. Repetitive stress injury happens when the same action is performed repeatedly. When stress is placed on a joint it pulls on the tissues around it. These tissues include muscles, tendons and bursae. Tendons are the strong flexible bands of tissue that attach muscles to bones.

-Rheumatoid arthritis (RA)

Rheumatoid arthritis (RA) causes inflammation in the lining of the joints and/or other internal organs. This inflammation separates RA from other more common forms of arthritis, such as osteoarthritis. It is a chronic disease, affecting many joints throughout the body, and resulting in damage to cartilage, bone, tendons and ligaments. RA causes the synovial lining of the joints to become inflamed. Researchers believe that the inflammation is triggered by the body's immune system failing to recognize body tissue as 'normal', therefore attacking it and bringing about joint damage. The damage becomes worse because the immune system's attack does not stop, and results in destruction of cartilage, bone, tendons and ligaments that can lead to permanent deformity and disability.


The name scleroderma is derived from the Greek word skleros, which means hard, and derma, which means skin. The full medical name of the condition is progressive systemic sclerosis.  This is sometimes shortened to just systemic sclerosis, as not all forms of scleroderma are progressive, or worsen over time. The most characteristic feature of scleroderma is the build-up of tough scar-like fibrous tissue in the skin. Less visible changes include damage to the cells lining the walls of small blood vessels.  This may in turn damage major organs.

-Sjögren's syndrome

Sjögren's syndrome is a chronic disorder that causes damage to the salivary glands, resulting in dry mouth, and the tear glands, resulting in dry eyes. It can also affect other parts of the body including joints, muscles and nerves, organs such as the lungs, kidneys, liver, pancreas, stomach and brain, or glands such as the thyroid gland.  Sjögren's syndrome can cause complete destruction of any of these areas. Since Sjögren's syndrome can affect the liver and pancreas, there is a greater chance of developing cancer of the lymph tissue.  However, this is an unusual and rare result.

Links to Arthritis

  • Arthritis Foundation
  • Arthritis Society
  • Versus Arthritis: This website is for anyone who wishes to know more about arthritis, the charity and how to help find the cure. Arthritis causes long term health problems for more than one in seven adults and many thousands of children. Versus Arthritis is the only UK charity wholly dedicated to curing it.
  • Arthritis Research and Therapy: Latest research and information on this topic.
  • Arthritis and Exercise: The amount and form of exercise recommended for each individual will vary depending on which joints are involved, the amount of inflammation, how stable the joints are, and whether a joint replacement procedure has been done. A skilled physician who is knowledgeable about the medical and rehabilitation needs of people with arthritis, working with a physical therapist also familiar with the needs of people with arthritis, can design an exercise plan for each patient.
  • Reactive Arthritis: This page contains general information about reactive arthritis. It describes what reactive arthritis is and how it develops. It also explains how reactive arthritis is diagnosed and treated. 
  • Arthritis and Rheumatic Diseases: This page answers basic questions about arthritis and rheumatic diseases.
  • Statistics on Arthritis: Arthritis and chronic joint symptoms affect nearly 70 million Americans, or about one of every three adults, making it one of the most prevalent diseases in the United States. As the population ages, this number will increase dramatically.
  • John Hopkins Arthritis Center