Arthritis main groups

Degenerative or mechanical arthritis

Degenerative or mechanical arthritis refers to osteoarthritis, a chronic disorder that damages the cartilage and tissues surrounding a joint. Osteoarthritis is sometimes called “degenerative joint disease” or “wear and tear” arthritis.

Osteoarthritis is the most common chronic (long-lasting) joint condition. A joint is where two bones come together. The ends of these bones are covered with protective tissue called cartilage. With osteoarthritis, this cartilage breaks down, causing the bones within the joint to rub together. This can cause pain, stiffness, and other symptoms. The main job of the smooth, slippery cartilage is to help the joints glide and move smoothly. Osteoarthritis causes the cartilage to become thinner and rougher. The cartilage at the ends of your joints is damaged. The cartilage becomes thinner and can sometimes disappear altogether. Your cartilage has a dampening effect and if the cartilage is no longer there, you have a lot of pain and difficulty in moving.
To compensate for the loss of cartilage and changes in joint function, the body begins to remodel the bone in an attempt to restore stability. This can cause undesirable bony growths to develop, called osteophytes. The joint can become misshapen. Osteoarthritis can also result from previous damage to the joint such as a fracture or previous inflammation in the joint. It occurs mainly in the neck, lower back, hips, knees or hands.

Osteoarthritis affects more than 30 million men and women in the U.S. and is a leading cause of disability. It affects most often older people, but can occur in adults of any age.

Soft tissue pain

Fibromyalgia is a condition characterized by aching and pain in muscles, tendons and joints all over the body, especially along the spine. There are measurable changes in body chemistry and function in some people with fibromyalgia that may be responsible for certain symptoms.
Fibromyalgia is a neurologic health problem that causes widespread pain and tenderness (sensitivity to touch). The pain and tenderness tend to come and go, and move about the body. Most often, people with this chronic (long-term) illness are fatigued (very tired) and have sleep problems. However, fibromyalgia is not associated with muscle, nerve or joint injury, inadequate muscle repair or any serious bodily damage or disease.
You are at higher risk for fibromyalgia if you have a rheumatic disease (health problem that affects the joints, muscles and bones). These include osteoarthritis, lupus erythematosus, rheumatoid arthritis or ankylosing spondylitis.

Fibromyalgia is most common in women, though it can occur in men. It most often starts in middle adulthood, but can occur in the teen years and in old age.

(Mixed) Connective tissue disease (CTD)

Mixed connective tissue disease has signs and symptoms of a combination of disorders, primarily lupus erythematosus, scleroderma and polymyositis. For this reason, mixed connective tissue disease is sometimes referred to as an overlap disease. In mixed connective tissue disease, the symptoms of the separate diseases usually don’t appear all at once. Instead, they tend to occur in sequence over a number of years, which can make diagnosis more complicated.

Connective tissues support, bind together or separate other body tissues and organs. They include tendons, ligaments, and cartilage. With certain rheumatic conditions next to your joints also skin and several internal organs in the body are affected, for example, lungs, heart or kidneys.
Connective tissue disease (CTD) is an autoimmune disorder. Connective tissue diseases are characterized by inflammation of tissues, caused by antibodies. The immune system makes an abundance of proteins called antibodies. Antibodies are made by white blood cells (B cells). The antibodies recognize and combat infectious organisms (germs) in the body. Antibodies develop in our immune system to help the body fight infectious organisms. When an antibody recognizes the foreign proteins of an infectious organism, it recruits other proteins and cells to fight off the infection. This cascade of attack is called inflammation.
Sometimes these antibodies make a mistake, identifying normal, naturally-occurring proteins in our bodies as being “foreign” and dangerous. When these antibodies make incorrect calls, identifying a normal naturally-occurring protein as foreign, they are called auto-antibodies. Auto-antibodies start the cascade of inflammation, causing the body to attack itself.
The antibodies that target “normal” naturally-occurring proteins within the nucleus of a cell are called antinuclear antibodies (ANA). ANA react with components of the body’s own healthy cells and cause signs and symptoms such as tissue and organ inflammation, joint and muscle pain and fatigue. These conditions are called autoimmune diseases. Included in this category are the following conditions: polymyositis, dermatomyositis, rheumatoid arthritis (RA), scleroderma, Sjogren’s syndrome, systemic lupus erythematosus and vasculitis.
People with diseases of connective tissue may have symptoms of more than one autoimmune disease. In these cases, doctors often refer to the diagnosis as mixed connective tissue disease.

Examples of (M)CTD include:
• Systemic lupus erythematosus (SLE) • Scleroderma • Sjogren’s syndrome • dermatomyositis.

Metabolic Arthritis

Gout is a metabolic arthritis disease. Uric acid is formed as the body breaks down purines, a substance found in human cells and in many foods. Some people have high levels of uric acid because they naturally produce more than is needed or the body can’t get rid of the uric acid quickly enough. Most uric acid dissolves in blood, travels to the kidneys and passes out in urine. In some people the uric acid builds up and forms needle-like crystals in the joint, resulting in sudden spikes of extreme joint pain – a gout attack.
Gout can come and go in episodes or, if uric acid levels aren’t reduced, it can become chronic, causing ongoing pain and disability.

Gout can come and go in episodes or, if uric acid levels aren’t reduced, it can become chronic, causing ongoing pain and disability. It commonly affects a single joint or a small number of joints, such as the big toe and hands.

Septic arthritis

Septic arthritis is most commonly caused by bacteria, but can also be caused by viruses and fungi. Bacteria are the most significant pathogens in septic arthritis because of their rapidly destructive nature. A bacterium, virus or fungus that enters a joint can cause inflammation. Organisms that can infect joints include:
• Salmonella and Shigella, spread through food poisoning or contamination.
• Chlamydia and gonorrhea, which are sexually transmitted diseases.
• hepatitis C, a blood-to-blood infection that may be spread through shared needles or transfusions.

A joint infection can often be cleared with antibiotics or other antimicrobial medication. However, the arthritis can sometimes become chronic and joint damage may be irreversible if the infection has persisted for some time.
An example is reactive arthritis.

Bone disorder

An example is Paget’s disease of bone, which is an uncommon, benign, chronic bone disorder.
Individuals with Paget’s disease experience rapid isolated bone repair, which causes a variety of symptoms from softer bones to enlarged bone growth, typically involving one or more bones of the pelvis, low back (spine), hips, thighs, head (skull) and arms. This can lead to problems such as bending, breaking, pinched nerves, arthritis and reduced hearing.
Medical therapies have proven effective in reducing the frequency of pain, fractures and arthritis that may be caused by this condition.