Why does learning new mental skills lead to headaches? Why is deliberate practice uncomfortable? For example, during learning college math and playing the piano. Why do we get headaches after long hours of practice?
According to this question, learning is about connecting distant neural networks; in forming these synapses resources are recruited such as calcium and glucose.
Now since the brain has no pain receptors, the discomfort must be coming from the surrounding nerves in the skull and neck. Possibilities:
a) Requiring greater resources is straining our blood system and hence the pain.
b) Forming many connections continuously creates excess of neurotransmitters such as glutamine that strain and literally swell brain areas, which in turn hit against our skull nerves.
Please feel free to correct me.
This topic is closely connected with the cellular mechanism of mental fatigue.
Migraine and tension-type headaches are an important burden in many people's daily lives. This is not my direct research topic. But as far as I have read on the subject headache has been related to posture problems and vision problems. Some studies point to an increase in headache complaints, related to increased hours of study online. But this can also be related to posture and vision (tired eyes or dry eyes). Of course, the occurrence of headaches can affect the quality of the study (and acquisition of new skills), but estimating the opposite apparently still lacks proof. I leave below some links of articles about the subject that may be of your interest:
Behavioral Treatments for Headache,
Headache vs musculoskeletal pain vs vision problems
Headach - clinical setting