Humira is a prescription medication used to treat various autoimmune conditions, including rheumatoid arthritis, Crohn's disease, and psoriasis. It works by blocking a protein called tumor necrosis factor (TNF), which plays a key role in inflammation and immune responses. Administered via injection, Humira helps reduce symptoms like pain and swelling, improving the quality of life for many patients. It is important for users to follow their healthcare provider's instructions and be aware of potential side effects, such as increased risk of infections.