When to use this diagnosis

• Clinical suspicion that caffeine contributes to symptoms (anxiety, palpitations, sleep disturbance) but full criteria for intoxication or withdrawal are not met.
• Presentation is atypical, transient, or occurs in a setting with limited history (ED, impaired capacity).
• Use as a temporary working diagnosis while further information or observation is obtained.

Common presentations

• Palpitations or tachycardia after unknown amount of stimulant-containing drinks/supplements.
• Anxiety, tremor or insomnia where recent caffeine use is reported but exact timing/amount unclear.
• Mild neurological symptoms such as headaches or lightheadedness temporally linked to caffeine changes.
• Occupational incidents where caffeine use is suspected but not confirmed.

Assessment checklist

1. Ask about sources of caffeine (coffee, tea, energy drinks, pre‑workout, OTC meds), estimated amounts and timing of last intake.
2. Evaluate symptoms: onset, duration, severity and associated features (chest pain, syncope, seizures).
3. Perform physical exam: vitals, tremor, diaphoresis, mental status.
4. Order ECG if palpitations, syncope or cardiac history present; check electrolytes if severe symptoms.
5. Consider brief observation or short admission when history is unclear and safety is a concern.

Initial management

• Stabilise ABCs in acute presentations; provide a calm environment and reassurance for mild cases.
• Hydration, rest and removal of further caffeine exposure are first steps.
• For significant anxiety or panic, consider short‑term benzodiazepine under supervision.
• For symptomatic tachycardia without structural heart disease, beta‑blocker can be considered in consultation with cardiology if needed.
• Document a safety plan and advise on gradual reduction of caffeine intake rather than abrupt cessation if dependence suspected.

Follow‑up and clarification

• Arrange outpatient review within days to reassess once more history or collateral is available.
• Use screening tools and timeline follow‑back to determine whether criteria for caffeine intoxication or withdrawal are met.
• Refer to cardiology for persistent arrhythmia or to psychiatry for ongoing anxiety or panic symptoms.
• Provide education on caffeine content and safer limits; consider workplace adjustments if safety is affected.