Rheumatoid arthritis (RA) is a chronic autoimmune disease in which the immune system attacks the synovium, causing joint inflammation, pain, swelling, and stiffness that may progressively damage cartilage and bone. It is more common in women and can develop at any age. Unlike ordinary joint pain associated with aging or physical strain, RA is a systemic inflammatory condition that can affect multiple organs and significantly influence a person's overall health and quality of life. Its development involves genetic susceptibility, environmental exposures, hormonal influences, and immune dysfunction. Smoking is a well-established risk factor, while the potential roles of air pollution and changes in the human microbiome are also being investigated for their possible contributions to disease development. The most common symptoms include persistent joint pain, swelling, tenderness, and prolonged morning stiffness, particularly in the hands, wrists, and feet. Fatigue and general weakness may also occur. Morning stiffness may last for an hour or longer, particularly during periods of active inflammation. As symptoms progress, everyday activities such as making a fist, opening containers, dressing, walking, or climbing stairs may become increasingly difficult. RA is a systemic condition that can affect organs beyond the joints. Persistent systemic inflammation can contribute to complications involving several organs and body systems. Lung involvement may include interstitial lung disease and pleural inflammation, and some patients may experience respiratory symptoms that require specialist assessment. Eye manifestations can range from dryness to more serious inflammatory conditions, such as scleritis. Some patients develop rheumatoid nodules beneath the skin, particularly around pressure points. Chronic inflammation may also contribute to anemia, persistent fatigue, muscle weakness, and an increased risk of cardiovascular disease. Diagnosis is based on a combination of clinical findings, the pattern and duration of joint involvement, laboratory investigations, and imaging results. Rheumatoid factor (RF) and anti-citrullinated protein antibodies (ACPAs), commonly assessed and can support the diagnosis. Inflammatory markers, including C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR), help assess inflammatory activity, although normal results do not necessarily rule out the disease. X-rays can identify established structural damage. Advances in treatment have substantially improved the outlook for people living with RA. Treatment aims to control inflammation, achieve remission or low disease activity, and preserve joint function. Conventional disease-modifying antirheumatic drugs (DMARDs) are commonly used to control disease progression. In addition to medication, regular physical activity, physiotherapy, a balanced diet, and maintaining a healthy weight are important aspects of disease management. Smoking cessation is especially important because smoking is associated with an increased risk of developing RA and may adversely affect treatment outcomes. Medication should not be stopped or changed without medical advice, even when symptoms improve, because inflammation may recur and cause further damage.