Q:

If the brain has no pain receptors, how come you can get a headache?

I've read many years ago in books, that the brain has no nerves on it, and if someone was touching your brain, you couldn't feel a thing.
Just two days before now, I had a very bad migraine, due to a cold. It's become better now, but when I had it I felt my head was going to literally split in half, as the pain was literally coming from my brain.
So it lead me to the question: How come people can get headaches if the brain has no nerves?

A:

Brain, indeed, cannot feel pain, as it lacks pain receptors (nociceptors). However, what you feel when you have a headache is not your brain hurting -- there are plenty of other areas in your head and neck that do have nociceptors which can perceive pain, and they literally cause the headaches.
In especially, many types of headaches are generally thought to have a neurovascular background, and the responsible pain receptors are associated with blood vessels. However, the pathophysiology of migraines and headaches is still poorly understood.

A:

You are correct in that the neurons themselves do not sense pain. However, the brain contains layers of coverings, blood vessels, the scalp and some muscles. All of these other structures have pain receptors. The coverings of the brain are called meninges and consist of the dura, arachnoid and pia. The dura in particular has a lot of pain receptors and may be responsible for many headaches. As a neurosurgeon I have seen this first hand during awake brain surgery when we open the dura. The patient usually doesn't report any pain when you drill a hole in their skull. However, they start to report dull pain or headache when you stimulate or touch the dura.

