Pathological altruism is when altruism is taken to an unhealthy extreme, and either harms the altruistic person, or well-intentioned actions cause more harm than good.
The term "pathological altruism" was popularised by the book Pathological Altruism.
Examples include depression and burnout seen in healthcare professionals, an unhealthy focus on others to the detriment of one's own needs, hoarding of animals, and ineffective philanthropic and social programs that ultimately worsen the situations they are meant to aid.
Mr. Lucy wrote a paper about Pathological Altruism, from a Psychological perspective those who are Pathologically Altruistic are doing what they do to boost their own low self esteem and therefore boost their own ego, so they are not being Altruistic out of empathy they are being Altruistic because of Egoism.
So Pathological Altruism is actually Psychological Egoism.
This is why I commented that the Leftist Maniacs are Pathologically Altruistic because they do what they do eg. the "poor refugees" thing because it makes them feel good about themselves, it boosts their own ego, they do not give a shit about the ultimate long term consequences of their Pathological Altruism.