At the doctor

Come in. What seems to be the problem?

I have had a headache for three days.

Is it worse in the morning or in the evening?

In the evening, usually after work.

How many hours a day do you look at a screen?

Nine, maybe ten.

That may be the cause. Try a break every hour and drink more water.

And if it does not get better?

Come back next week and we will look again.