One of the major conflicts in the play is between young, 23 year old, tubercular Edmund (based on O'Neill himself) and his mother. Edmund has suffered growing up alongside his mother's morphine addiction, which has led her to be withdrawn and not a real, accessible parent to him. As her ghostly appearance indicates, she is more ghost than angel of the home. Edmund also carries the guilt that she got addicted to morphine due to giving birth to him and is back on the morphine because he has been diagnosed with TB.
As the loving, peacemaking one, Edmund has tried to escape by going to sea, but of course ends up back home. Yet he gets angry at his mother for her similar escapism, which left him emotionally stranded, as it still does:
The hardest thing to take is the blank wall she builds around her. Or it's more like a bank of fog in which she hides and loses herself. Deliberately, that's the hell of it! You know something in her does it deliberately—to get beyond our reach, to be rid of us, to forget we're alive! It's as if, in spite of loving us, she hated us!
Edmund describes his time at sea in terms of fog too—his fog of escape is not that different from his mother's, but neither escape changes the family situation, a conflict that simply doesn't resolve.