A joint is a movable connection between two bones and consists of the adjacent parts of the bones, the joint surface covered with cartilage, and the synovial membrane (synovium), which produces the “joint lubricant” (synovial fluid). Cartilage and synovial fluid provide cushioning to distribute the load on the joint, especially in weight-bearing joints. They are necessary for movement to run literally “smoothly,” without friction. The joint is surrounded by the joint capsule, which is also lined on the inside with synovial membrane and reinforced on the outside by connective tissue, tendons and ligaments.
When a joint becomes inflamed, more synovial fluid is produced, causing the joint to swell and usually also to cause pain (“arthralgia”). If the joint inflammation persists (“arthritis”), the synovial membrane thickens, which can lead to destruction of the cartilage and ultimately attack the bone itself. This results in chronic joint pain and, over time, joint destruction.
Rheumatism – what is it, anyway?
The term “rheumatism” comes from Greek and means flow or stream, stemming from the ancient idea that incorrectly composed bodily fluids at certain changing locations in the body (joints, organs, etc.) lead to fluid congestion and thus to painful inflammation. Among both laypeople and professionals, the terms “rheumatism” and “rheumatic complaints” are not clearly defined, unlike the term “rheumatic diseases,” which in turn must not be equated with “rheumatic symptoms.”
Everyone knows the word “rheumatism,” and almost everyone thinks they know what it means. Nevertheless, many misconceptions surround this common widespread condition, and we would like to clear them up. The assumption that rheumatism is a disease of older people is just as wrong as the popular belief that rheumatism is caused by dampness. The idea that a focus of inflammation in the body (e.g., abscessed teeth or tonsils as a so-called “focus”) could cause rheumatism is also incorrect.
In many rheumatic diseases, the immune system mistakenly targets the body’s own tissue—this is known as an autoimmune reaction. In particular, joints, tendons or internal organs are attacked, leading to chronic inflammation. This immune dysregulation is a key trigger for conditions such as rheumatoid arthritis or systemic lupus erythematosus. Genetic predisposition and environmental factors such as infections or smoking may play a role.
Rheumatism can also affect internal organs: When people talk about “rheumatism,” many primarily think of painful, swollen joints. However, rheumatism can also affect internal organs. In so-called collagenoses, for example, this can lead to hardening of the skin, kidney inflammation, scarring in the lungs, or even stroke. In recent years, rapidly growing insights in the field of immunology have made a decisive contribution to a better understanding of these diseases.
Musculoskeletal diseases lead to persistent pain and restricted mobility—around 25% of the adult European population is affected, including about 17 million people in Germany. In around 20% of all patients who see a doctor for this reason, symptoms from the rheumatic spectrum can be diagnosed. Diseases of the musculoskeletal system account for around 30% of occupational and reduced-earning-capacity pensions. Medications for rheumatic symptoms have for years been the most frequently prescribed group of medicines in the Federal Republic of Germany.
Alongside mental illnesses and heart/lung diseases, rheumatic diseases are among the most common—and, in economic terms, the most costly—conditions. As chronic diseases, they account for a high proportion of all illnesses found in the population.
Classification of rheumatic diseases
1. Inflammatory rheumatic diseases (here: links to the conditions for each term)
- Rheumatoid arthritis
- Chronic polyarthritis
- Spondyloarthritis
- (inflammatory spinal diseases)
- Psoriatic arthritis
- Polymyalgia rheumatica
- Collagenoses
- Systemic lupus erythematosus
- Sjögren’s syndrome
- Systemic sclerosis (scleroderma)
- Polymyositis / dermatomyositis
- Mixed connective tissue disease
- Vasculitides
2. Wear-related (“degenerative”) diseases
- Polyosteoarthritis of the fingers
- Heberden’s osteoarthritis (distal finger joints)
- Bouchard’s osteoarthritis (middle finger joints)
- Rhizarthrosis (thumb carpometacarpal joint)
- Spondyloarthrosis (wear-related spinal diseases)
- Coxarthrosis (osteoarthritis of the hip joints)
- Gonarthrosis (osteoarthritis of the knee joints)
- Osteoporosis
3. Soft-tissue rheumatic syndromes
- Periarthropathies
- Tendomyopathies
- Myopathies
- Myogeloses
- Entrapment syndromes
4. Pararheumatic syndromes and symptoms in other, non-rheumatic diseases
- Crystal arthropathies (e.g., “gout”)
- Arthropathies in internal medicine diseases
- Infectious arthritis
- “Paraneoplastic rheumatoid”
Diseases in group 1 are also referred to as “rheumatic diseases in the narrower sense,” in contrast to the conditions in groups 2, 3 and 4.
Why see a rheumatologist?
Symptoms affecting the musculoskeletal system can have many causes. They range from harmless discomfort to severe inflammatory rheumatic diseases. Every patient with an inflammatory rheumatic disease should be co-managed by an internal medicine rheumatologist at the onset of the disease and then at regular intervals. Only in this way can optimal care be ensured. Early diagnosis and initiation of treatment, as well as consistent monitoring of therapy and disease control, help to relieve pain, prevent flare-ups and damage, and maintain quality of life and participation in everyday life. The reality is different: the diagnosis is usually made only after valuable time to influence the course of the disease has already been lost. In many cases, the quality of treatment also falls short of what is medically possible because only 10% to 20% of those affected receive specialist rheumatology care at all.
