I've been trying to prevent my Russian from rusting by going through Duolingo in both directions (Russian for English speakers and English for Russian speakers). I found "I have a headache" being consistently translated as "у меня болит голова" in the Russian lessons, and as "у меня головная боль" in the English lessons.
I gather that they have the same meaning, but are they exact synonyms or this there a nuance between them? Maybe one of them is more childish or more casual or something else?
Thanks in advance.