Headaches question

Hola Steve

In this test-question: 

Antes a menudo me dolía la cabeza, pero ahora no. 

Before, I used to have headaches often, but not anymore.

we are using doler in singular with "la cabeza" because that's how we say in Spanish "to have a headache" ( = my head used to hurt), however the translation used in English is not literal in this case, it's using the expression in plural "I used to have headaches" because it'd sound odd to say "I used to have a headache" - you'd use it in plural. 

I hope this clarified it.

Saludos

Inma