So, as always, if you have frequent severe headaches or migraines, document in a journal and GO for medical treatment if it arises to a place where you can't function in running your life that day or getting to and staying at work. This is the ONLY way to develop the required medical evidence. SOJ.
The challenge of proving disabling headaches: Recently, in late 2019, the SSA provided us some guidance on the evaluation of headache / migraine impairments. As sufferers of chronic migraine, and some lesser form of headaches are well aware, such head pain can leave someone unable to care for their own basic needs temporarily, much less get to work on time or at all that day or for a few days. But headaches are hard to see and harder to prove, so if you have such a severe impairment and know yourself to be actually disabled from it, you need to get a sense of what evidence you need to build via your actions with regard to your medical treatment and daily activities.
"[A] primary headache disorder is a diagnosis of exclusion, diagnosed 'only after excluding alternative medical and psychiatric causes of a person’s symptoms.'” NOSSCR.org citing SSR 19-4. This kind of method of diagnosis, that of exlcuding other in a narrowing down of possibilities, is often seen with impairments of which the medical community has not yet discovered a blood marker or other diagnostic scientific test in which to affirmatively diagnose a condition without the need for consideration and exclusion of other ailments that may present such a symptom.
TIP: The SSA advises that a well-kept and documented “headache journal” is helpful to physicians. We urge them because they are also potentially helpful to your judge. So keep one. This is wise with many other conditions with on and off symptomology, so arguably all claimants should be keeping a symptom journal.
Note that one must have a "Primary" headache disorder and not a "secondary" headache disorder: "[O]nly a primary headache disorder can be considered a MDI [medically determinable impairment], not secondary headaches because 'secondary headaches are symptoms of another underlying medical condition.'”
Here is what SSA will look at, from your durational treatment records, to determine if you do have an MDI:
1) A diagnosis with documentation that the AMS [acceptable medical source] “reviewed the person’s medical history, conducted a physical examination, and made the diagnosis of primary headache disorder only after excluding alternative medical and psychiatric causes of the person’s symptoms...” along with treatment notes consistent with the diagnosis; ["along with teatment notes" - don't think just getting your doctor out of the blue to give the diagnosis. Your historical records with that doctor will have to show supporting commentary leading up to this diagnosis, over months or years]
2) An observation of a typical headache event and a detailed description of the event by an AMS, including co-occurring observable signs, or a third-party in the absence of direct observation by an AMS; [this may mean getting to an urgent visit when suffering the headache/migraine, or the ER, instead of just talking about it after the fact, when you visit your doctor]
3) Laboratory test findings; and
4) Responses to treatment, such as medications. [if medications sufficiently reduce or eliminate the the disabling symptoms that result from the headaches, then they suffice to make a person, gratefully, no longer disabled by them]
So, as always, if you have frequent severe headaches or migraines, document in a journal and GO for medical treatment if it arises to a place where you can't function in running your life that day or getting to and staying at work. This may be the ONLY way to develop the required medical evidence to have it as an established MDI.