Write a clear sick message to work

Help me write a sick message to work.

Channel: [text / email]
Expected absence: [today / until date / unsure]
What I'm willing to share: [unwell / a bit more]
Manager name: [optional]

Ask me up to 3 short questions first if anything important is missing. Wait for my answers.

Then:
1. A short message.
2. A follow-up if it continues.
3. Reminder about self-certification / fit notes in general UK terms to check with employer/NHS.
4. If I'm severely unwell, seek medical help rather than only messaging work.

Only use what I've told you, leave blanks for anything I haven't given, and don't invent diagnoses, doses, calorie targets or treatment plans. This is help with preparation, planning and wording, not medical, diet or treatment advice; check the NHS website, speak to a pharmacist, or contact NHS 111; call 999 if it feels like an emergency. UK English.

Stay in this ChatGPT chat. Do not turn on apps or connectors, and do not use memory from another chat.