Retrieval-augmented generation (RAG) grounds an LLM's answers in your own trusted documents. Instead of letting the model answer purely from what it absorbed in training, RAG first retrieves the relevant passages from a controlled corpus — clinical guidelines, drug formularies, your organization's own protocols — and then conditions the model's response on those passages, ideally with citations back to the source. The generation step becomes closer to grounded summarization of retrieved material than open-ended invention.

For a telemedicine product, this addresses two of the biggest problems with using LLMs in a clinical context. It reduces hallucination by anchoring answers to real documents the clinician can verify, and it keeps answers current — when a guideline or formulary changes, you update the corpus rather than retraining a model, so the system reflects today's protocol rather than a frozen training snapshot. The citations also support the transparency that clinical decision support depends on.

The critical implication is that the retrieval layer becomes part of your safety case, not just a performance optimization. If a stale, superseded, or simply wrong document sits in the corpus, RAG will retrieve it and the LLM will present its contents as a confident, sourced answer — bad input propagates straight into authoritative-looking output. So corpus governance (what is in it, who curates it, how it is kept current and versioned) is a clinical-safety responsibility. The common mistake is treating RAG as a finished safeguard once it is wired up, while neglecting the discipline of keeping the underlying documents correct and current.