Managing high cardinality data is crucial for optimizing resource usage and performance in Prometheus monitoring systems, especially when dealing with cloud-native environments that can experience sudden spikes in cardinality. High cardinality leads to increased memory usage, storage requirements, query latency, resource intensiveness, and scalability challenges. To manage high cardinality data from Prometheus, it is essential to set up scrape jobs with meaningful labels, reload configurations without restarting the server, check existing cardinality, view most expensive jobs, omit scrape jobs from remote write, reduce cardinality of a scrape job by dropping high cardinality labels or datapoints entirely, and store data for shorter periods. By implementing these strategies, users can strike a balance between gathering detailed data and managing costs in their Prometheus monitoring systems.