Brain metastasis refers to the spread of cancer cells from a primary tumor located elsewhere in the body to the brain. This is a common complication of many types of cancer, particularly lung, breast, melanoma, kidney, and colorectal cancers. Brain metastasis can cause symptoms such as headaches, seizures, cognitive impairments, and neurological deficits. Treatment options for brain metastasis may include surgery, radiation therapy, chemotherapy, and targeted therapy. Research in this area focuses on understanding the mechanisms of metastasis to the brain, improving diagnostic techniques, developing new treatments, and improving outcomes for patients with this condition.