CTCAE (Common Terminology Criteria for Adverse Events)
A simplified tool to help grade the severity of common adverse events from medical treatments, especially in oncology, using CTCAE-style grades (0–5).
Select an adverse event and then choose the description that best fits the clinical situation. Press “Calculate” to show the CTCAE-style grade and interpretation.
This helper uses summarised CTCAE principles and paraphrased descriptors. Always consult the full official CTCAE (v5 or v6) when grading for clinical trials, regulatory reports, or formal documentation.
This tool is intended for use by health professionals for educational and bedside estimation only. It does not replace official CTCAE resources, trial protocols, institutional guidelines or clinical judgement. Final grading and management decisions must be based on the full clinical context and the current CTCAE version.
CTCAE (Common Terminology Criteria for Adverse Events) is the standard language used worldwide to describe and grade side effects from cancer treatments and many other medical interventions. It was developed by the US National Cancer Institute (NCI) and first released in the early 1980s to harmonise how adverse events (AEs) were recorded in oncology trials.DermNet®+1
Each AE (for example fatigue, neutropenia, nausea, rash) is defined as a specific term, and then graded on a 5-point severity scale:
- Grade 1 – mild
- Grade 2 – moderate
- Grade 3 – severe or medically significant but not immediately life-threatening
- Grade 4 – life-threatening consequences
- Grade 5 – death related to the adverse event.Wikipedia+1
The grading reflects not only symptoms, but also impact on daily activities, need for intervention, hospitalisation, and dose modification.PMC+1 CTCAE terms are organised by MedDRA system organ class (e.g. “Blood and lymphatic system disorders”, “Gastrointestinal disorders”, “Skin and subcutaneous tissue disorders”), and for each term CTCAE provides detailed criteria for grades 1–5.DermNet®+1
CTCAE has evolved through several versions (2.0, 3.0, 4.0, 5.0), and version 6.0 was released in 2025, continuing its role as the gold standard for AE reporting in cancer clinical trials and drug development.Wikipedia+1 It is used daily by oncologists, research nurses, data managers and regulators to:
- Standardise toxicity reporting across centres and trials
- Guide dose reductions, treatment interruptions, or discontinuation
- Support safety monitoring, approvals and labelling of new therapies.Cancer.gov+1
Important: CTCAE is a detailed, copyrighted NCI resource. The calculator below is a simplified educational helper that paraphrases some common AE grades. It does not replace the official CTCAE v5/v6 tables for research or regulatory documentation.
