In old age

[Allen165]

Examples of common coexisting diseases in old age:

"At old age" would be wrong, right?

Thanks.

 

[2006]

Examples of common coexisting diseases in old age:

"at old age" would be wrong, right? Yes, it would be wrong.

Thanks.

2006

 

[Raymott]

Examples of common coexisting diseases in old age:

"At old age" would be wrong, right?

Thanks.

Yes.
But note:
"This injury would be more serious at an older age [than that of the current patient]". Not "in an older age".
"You're unfortunate to have these coexisting illness at such a young age". Not "in such a young age".