Memory leaks in Node.js often occur from unclosed connections, excessive caching, or inefficient data handling. Review these areas to prevent memory build-up.

Memory leaks in Node.js applications can lead to performance degradation, often resulting from unclosed database connections, unhandled promises, or inefficient data caching. Start by profiling memory usage with Node’s built-in tools like --inspect and --prof, which help identify functions consuming excess memory. Common causes include unclosed database connections, particularly in MongoDB and SQL, so ensure proper closing patterns. Additionally, review caching strategies—especially in memory-intensive applications—to avoid retaining redundant data. In the case of event listeners, remove them when no longer needed, as excess listeners can prevent garbage collection. Using tools like clinic and pm2 helps monitor memory in production environments, alerting you to increases in memory use.