Most of us get headaches from time to time. Some are mild. Others cause throbbing pain. They can last for minutes or days. There are many types of headaches. How you treat yours depends on which kind you have. Headaches might arise because of another medical condition, such as swollen sinuses or head injury. In these cases, treating the underlying problem usually relieves headache pain as well. But most headaches—including tension headaches and migraines—aren’t caused by a separate illness. A headache may feel like a pain inside your brain, but it’s not. Most headaches begin in the many nerves of the muscles and blood vessels that surround your head, neck, and face. These pain-sensing nerves can be set off by stress, muscle tension, enlarged blood vessels, and other triggers. Once activated, the nerves send messages to the brain, and it can feel like the pain is coming from deep within …