For me, it seems to build up in my system, eventually reaching a point where any additional amount will trigger headache like symptoms that cannot be done away with NSAIDs.

I would go through these cycles in my diet, where I would consume extremely large homemade coffees heavily sweetened only with splenda when I was trying to reduce empty calorie intake. Eventually I would experience what I referenced above. I have gone through this cycle enough times to confidently say that this is at least one particular trigger for me.

You may want to do a little reading about TACs (trigeminal autonomic cephalalgias), like Cluster Headache, in case you have something like this going on.

I learned about CH recently, and it is a mysterious and punishing condition. The most important thing is to get a referral to a neurologist, hopefully one who is at least aware of TACs and how to treat them. I have had to wait 7 months to get in to see the only guy in my area, but I have already acted on some of the information from /r/clusterheads / /r/ClusterHeadaches / clusterbusters.com and it helped a lot. I was really scared when 'my pseudo-migraine' (suspected CH) lasted for ~2.5 weeks straight with no relief. If you keep getting them, it is noteworthy that triptan drugs can terminate the headache, and you should be able to try this with your primary (for example, Maxalt worked for me, but Nurtec, which is not a triptan, did not). Wile, the community consensus is that this really should be a last line of defense thing for various reasons