A headache diary can be valuable in helping you and your doctor diagnose and treat your headaches. You can use it to map out the characteristics of your headaches, including their frequency, duration, and intensity. A diary can also help identify possible triggers and related symptoms, as well as track the dosage and effectiveness of any medications you’re taking.
Source: Keeping a headache diary
This would be a good template to follow for any chronic symptom like stomach issues, migraines, or inflammation.
I’ve met people who complain about things like recurring nausea or dizziness, yet refuse to take steps to track events leading up to these symptoms. Yeah, it can be a pain sometimes, but that data can go a long way with regards to making lifestyle choices, and it can certainly help your physician determine a better treatment plan if comes to that.