Our Gemara on Amud Beis discusses the dangers of cursing someone and how it can backfire:
Rav Yehuda says that Rav says: All the curses that David invoked upon Joab were ultimately fulfilled in David’s descendants, due to the curse that Solomon accepted upon himself. David cursed Joab: “Let the house of Joab never lack those who are afflicted with a discharge, or a leper, or who hold onto a staff, or fall by the sword, or lack bread” (II Samuel 3:29)... (These curses befell David’s descendants—Rehoboam, Uzziah, Asa, and Josiah.)...This explains the adage: “Be the one who is cursed, and not the one who curses, for a curse eventually returns to the one who curses.”
The Maharsha makes the following observation:
Even though most of these individuals were punished because of their own sins—Uzziah, whose heart became haughty and sought the priesthood for himself; Asa, about whom it is stated in Sotah (1:6) that he was punished because he imposed forced labor on Torah scholars; and Josiah, who was punished for not listening to Pharaoh Necho, as instructed by Jeremiah—nevertheless, were it not for David’s curse, it is possible that their sins would have been atoned for with a lighter punishment than what they ultimately received.
How do we understand this? As observed in previous articles on this blog, the spiritual world and the physical world follow similar patterns because they share the same Creator, governed by deeper spiritual universals that act as the "DNA" of everything. Just as physical diseases can have various causes, so too in the spiritual realm: a person might have a weaker spiritual immune system, and an “opportunistic” spiritual ailment can take over. There may also be other spiritual conditions that lead to cascading consequences. So, in this case, due to the toxic effects of David’s curse, these individuals, when committing specific sins, were more vulnerable to receiving punishment quickly, rather than having more time to repent or receiving more divine mercy.
This Gemara and Maharsha illustrate an important theological principle in understanding certain statements by our sages that seem to predict global doom or punishment. For example, teachings that say, “Whoever does or doesn’t do such-and-such will suffer such-and-such a fate,” as found in Mishna Shabbos (2:6), which predicts death during childbirth for certain sins, or Gemara Berachos (31b), which states that someone who is brazen and rules on a halachic matter in front of their master is liable for death. Likewise, our tradition acknowledges the noxious effect of the Evil Eye and the taboo against stating negative or dreaded outcomes to avoid bringing them about (see Berachos 19a: “al yiftach adam piv la-Satan”).
If we view these teachings not as guaranteed consequences, but as illustrating the toxic effect of sin, they begin to make more sense. For example, we all agree that cigarettes are toxic, and no doctor would recommend deliberately inhaling someone else’s smoke. Yet, while it may be unlikely that one specific exposure will cause cancer or lung disease, it is still absolutely toxic. When our sages say that doing or not doing certain things makes one liable for a specific consequence, they are warning about exposing oneself to spiritual toxicity that could accelerate and lead to dire consequences, including death or other forms of doom. This can be understood as the “secondhand smoke of Judaism” effect, which is helpful for those who have excessive fears or struggles with the literal meaning of these teachings.
Translations Courtesy of Sefaria, except when, sometimes, I disagree with the translation 
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