Metastatic bone disease occurs when cancer cells spread from their original site to the bones. This can happen with various types of cancer, including breast cancer, lung cancer, and prostate cancer. The cancer cells can weaken the bone structure, leading to pain, fractures, and other complications. Symptoms of metastatic bone disease may include bone pain, swelling, and increased risk of fractures. Diagnosis typically involves imaging tests like X-rays, CT scans, or MRIs, along with blood tests. Treatment options may include medications, radiation therapy, or surgery to manage symptoms and improve quality of life.