How to clear list of medical problems from Add/Edit Issue?

When adding medical problems, at the top of the Add/Edit Issue dialog is Type: Problem and a list:

  • asthma
  • BCC
  • Dermatocalasis
  • diabetes
  • etc
    “(Select one of these, or type your own title)”

Where is the contents of this list defined please? How do I remove everything from the list?

Thanks

A picture tells 100 words. Fantastic, thank you @stephenwaite