concerning

causing worry

comparative with more [more]

• The test results are a little concerning.
• It's concerning that nobody has heard from her.
• There has been a concerning rise in the number of accidents.

Compare worried (worried describes the person who feels the worry; concerning describes the thing that causes it)

on the subject of; about

Used mainly in formal writing such as letters, notices, and reports, where about would sound too casual: concerning your recent order; a report concerning safety at the factory. In ordinary speech, about is the natural choice.

• The letter contained information concerning the new policy.
• She had some questions concerning her contract.
• Concerning your request, we need a few more details.

Synonyms about (about is the plain, everyday word; concerning is more formal)