ICD-11 classes
21 Symptoms, signs or clinical findings, not elsewhere...
Mental or behavioural symptoms, signs or clinical findings
MB21 — Symptoms, signs or clinical findings involving cognition
MB21.A — Poor concentration

ICD-11 MB21.A — Poor concentration

Difficulty focusing attention and sustaining the mental energy necessary to accomplish a task or goal.

The diagnosis includes nothing.

The diagnosis excludes nothing.

It has no clarifying diagnoses.