> ## Documentation Index
> Fetch the complete documentation index at: https://docs-xcor.paloaltonetworks.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Identify issues behind suspicious trends

> Learn how to use Differential Diagnosis to identify issues in your telemetry data most closely correlated with suspicious behavior.

When troubleshooting issues, finding the root cause of a problem as quickly as
possible is critical. Palo Alto Networks Cortex XCOR includes
the Cortex XCOR Differential Diagnosis (DDx) feature to help developers find the source
of slowdowns or
failures by identifying suspicious trends in your telemetry data and what's causing
them.

DDx lets developers resolve service performance issues without
writing queries or needing knowledge of the entire system. DDx
ranks and highlights the most probable sources of issues so developers can test
hypotheses and compare trends to identify root causes.

## Identify issues in traces

In Trace Explorer or from service pages, use
[DDx for traces](/investigate/analyze/differential-diagnosis/traces) to
identify trends and immediately scan through all related tags and values to pinpoint
the exact `tag:value` pairs most closely correlated with suspicious behavior.

## Identify trends in metrics

In Metrics Explorer or from service pages, use
[DDx for metrics](/investigate/analyze/differential-diagnosis/metrics)
to examine time series anomalies, such as unusual shapes in their metrics like
spikes and dips, and quickly understand what dimensions are contributing to an issue.


## Related topics

- [Service pages](/observe/services/service-pages.md)
- [Ingest, query, and control your trace data](/overview/types/traces.md)
- [Trace Explorer features overview](/investigate/querying/traces/features.md)
- [Identify issues behind suspicious metrics trends](/investigate/analyze/differential-diagnosis/metrics.md)
- [Identify issues behind suspicious tracing trends](/investigate/analyze/differential-diagnosis/traces.md)


This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.