system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: If the brain lacks nerve endings for pain, how do we feel headaches?

I've heard that the brain itself has no "nerve endings" ^((terminology?)^) for touch/pain.  I know when I feel, I can tell where on my body the feeling is.  And, I know when I have a headache, the pain seems to come from where my brain would probably be.

So, why can I feel there, if I can't feel there?

P.S.:  I've heard the nerve endings we feel are actually in the nasal cavity, but most people just grow up imagining them as the head since pressure there works, is this true? or...
gpt
There are many types of headaches. The most common is tension headaches. These don't originate in your brain. They come from the pain receptors around your skull, not from your brain. Sinus headaches come from inflamation of your sinuses. You do have pain receptors near your brain. If you have a brain hemorrhage which is putting pressure on the inside of your skull, you will feel it. Your brain isn't doing the feeling, the receptors around your brain are doing the feeling. Dehydration causes headaches because it causes your brain to shrink and pull on the inside of your skull. Headaches can also be caused when the networks in your brain that are associated with processing pain are activated.