The phrase "a highly worrying" is correct and usable in written English.
It can be used to describe something that causes significant concern or anxiety.
Example: "The report highlighted a highly worrying trend in the increase of pollution levels in urban areas."
Alternatives: "a deeply concerning" or "a very troubling".
We have the feeling that, even within a highly worrying economic situation, this country has recovered something that we had lived – and lost – at the time of the transition after Franco: hope!
In a world defined by trends, we've been beset by a highly worrying one: There is an undeniable lack of IPOs.
If they don't, or can't, work together there could be a highly worrying conflict over scarce energy resources whenever recovery begins.
The MI6 chief, Sir John Sawers, told the committee there was the risk of "a highly worrying proliferation around the time of the regime fall".
The environment minister, Marina Silva, called the new data "highly worrying" and promised "emergency action," although no specific proposals were offered.
She protested against battery birds and thought "wonderful men" being given sandwiches, rather than meat and two veg, was highly worrying.
Because he was the Qaeda figure most directly involved in the reconnaissance, the fact that Mr. Hindi was at large was seen as highly worrying to American officials last weekend, after the discovery of computer files in Pakistan first provided the Bush administration with information about the scope and sophistication of the surveillance.
Digging below the headline number for overall economic expansion the picture in Germany is highly worrying: German exports fell by 5.8% from July to August while industrial production saw its biggest decline since 2009 over the same period, contracting by 4.8%.
Since anorexia has the highest mortality rate of any psychiatric disorder, these figures are highly worrying.
These six segments formed a continuum, from a segment of people who were highly worried, involved and supportive of policy responses (18%), to a segment of people who were completely unconcerned and strongly opposed to policy responses (7%).
· Currently, public health experts are highly worried about one of the deadliest strains of avian flu spreading in China and causing a surge in human infections.
