tunnel syndrome caused by compression of the median nerve by swelling around the wrist. Rheumatoid disease of the spine can lead to myelopathy. Atlanto-axial subluxation can occur, owing to erosion of the odontoid process and/or transverse ligaments in the cervical spine's connection to the skull. Such an erosion (>3mm) can give rise to vertebrae slipping over one another and compressing the spinal cord. Clumsiness is initially experienced, but without due care, this can progress to quadriplegia or even death. Constitutional symptoms Constitutional symptoms including fatigue, low grade fever, malaise, morning stiffness, loss of appetite and loss of weight are common systemic manifestations seen in people with active RA. Bones Local osteoporosis occurs in RA around inflamed joints. It is postulated to be partially caused by inflammatory cytokines. More general osteoporosis is probably contributed to by immobility, systemic cytokine effects, local cytokine release in bone marrow and corticosteroid therapy. Cancer The incidence of lymphoma is increased, although it is uncommon and associated with the chronic inflammation, not the treatment of RA. The risk of non-melanoma skin cancer is increased in people with RA compared to the general population, an association possibly due to the use of immunosuppression agents for treating RA. Teeth Periodontitis and tooth loss are common in people with rheumatoid arthritis. Risk factors RA is a systemic (whole body) autoimmune disease. Some genetic and environmental factors affect the risk for RA. Genetic Worldwide, RA affects approximately 1% of the adult population and occurs one in 1000 children. Studies show RA primarily affects individuals between the ages of 40–60 years and is seen more commonly in females. A family history of RA increases the risk around three to five times; as of 2016, it was estimated that genetics may account for between 40 and 65% of cases of seropositive RA, but only around 20% for seronegative RA. RA is strongly associated with genes of the inherited tissue type major histocompatibility complex (MHC) antigen. HLA-DR4 is the major genetic factor implicated – the relative importance varies across ethnic groups. Genome-wide association studies examining single-nucleotide polymorphisms have found around one hundred alleles associated with RA risk. Risk alleles within the HLA (particularly HLA-DRB1) genes harbor more risk than other loci. The HLA encodes proteins which controls recognition of self versus nonself molecules. Other risk loci include genes affecting co-stimulatory immune pathways, for example CD28 and CD40, cytokine signaling, lymphocyte receptor activation threshold