Dream about blood in sink is a metaphor for small annoyances and minor problems. You are not letting minor issues bother you. You may be trying to compensate for the sadness or stress in your life. This signals the obstacles that you need to overcome in order to succeed. You are losing sight of your ambitions and goals.
Blood in sink dream states some aspect of your relationship with your sibling, whether it one of sibling rivalry, nurturance, protectiveness, etc. Something in your life does not feel quite real. You are having problems with the feminine aspect of yourself. The dream signals deception and temptation. You need to get down to the core of some matter.
If you dreamt about blood in sink:
Whether it was intentional or not, it would perhaps be better to find out the real cause rather than have them withdraw in a sulk. Whatever may have sparked off your outburst can be healed with honesty. You just need to get the right perspective on the whole situation.