Wearable applications require power sources that are flexible, affordable, compact, and easily accessible. However, conventional power electronic devices are impractical due to their heaviness and rigidity. Additionally, batteries and external power sources have limited lifespans and applications, posing challenges for implanted and wearable devices that require consistent energy supplies. To overcome these challenges, 1D energy-related technologies have been developed, with nanogenerators emerging as an ideal power source. They can generate biomechanical energy from physical activities like muscle contraction and heartbeat and convert it into electrical signals for various applications, including biological indicator detection, cardiac pacing, nerve stimulation, and tissue repair. This review provides an overview of piezoelectric nanogenerators (PENGs) and recent progress in their development, with a focus on biomaterial-based PENGs for healthcare monitoring. Furthermore, the review discusses the future prospects and challenges of optimizing PENGs.