I cry for no reason

"For no reason" usually describes the absence of an immediate trigger, not the absence of a cause. Crying is a discharge of the nervous system, and the threshold at which it fires drops when the background load is high.

Mechanically: prolonged stress keeps the nervous system activated. In an activated state, the capacity to absorb anything else falls. A trifle — a song, a tone of voice, an advert — becomes the drop that crosses the threshold, and the reaction looks disproportionate because the visible trigger is small, not because the reaction is wrong.

That also explains the relief afterwards. Crying lowers activation; it isn't a loss of control, it's the system discharging.

Don't stop it. Holding back tears maintains the activation that produced them. If you can, let it pass — it usually takes a few minutes.

Log the context, not just the episode. What happened that day, how much you slept, what you ate, what conversation came before. After two weeks a pattern becomes visible — and there almost always is one.

Check the fundamentals. Sleep, regular food, alcohol. Sleep deprivation alone lowers the emotional threshold measurably, and alcohol lowers it the following day.

Name the emotion, even if it seems there isn't one. "I'm crying and I don't know why" often becomes "I'm crying and I'm exhausted" after thirty seconds of asking. Labelling reduces intensity.