Learning to do the things on our own that are necessary to help us survive and thrive is the key to effective self care. Having adequate food, water, and a warm shelter with clean air to breath is necessary for basic survival, and having caring social connections and a sense of purpose can be necessary for thriving emotionally
Self care is not an official medical term, to my knowledge, and it can involve emotionally supportive strategies that may not also be recommended as an effective care recommendation.
Strategies that are both emotionally and physically healthy would be the better choice for daily habits for health maintenance and save the less physically healthy but emotionally satisfying treats for less frequent use, but that suggests we have the research or the personal experience to know which strategies are less physically healthy.
That is where information based on effective health care research can help make self care choices more likely to be beneficial and effective for supporting long term health.