Self-awareness arises from feeling. It is the totality of all of one's body feelings at any given time. Stated another way, self-awareness is simply knowing what one feels, what one is actually doing. Where feeling is low due to muscle tension and suppression, there often arises a substitute to self-awareness, self-consciousness.
Self-consciousness is a mental focus on the possible judgment others will make about one's actions and statements. This has an inhibitory effect, and though some actions will be allowed through the 'internal censor', they will lack naturalness, because shame is always present. Self-consciousness is seeing oneself from the outside, from the 'mind's eye' so to speak, because one cannot see or feel from the inside. The body is recognized as one's own but is not felt, so there is usually an awkwardness and tension in expression and movement. This is sometimes called having an observing ego.
Self-consciousness can lead to some social deftness in structured situations, but still not intrinsically lead to strong human contact. As a product of the mind and ego, self-consciousness is at great risk of distortion by ego images and goals, and it wanders quickly from the present reality to future fantasy and past memories. The tendency to hold back is also mistaken for self-possession. Holding back is considered a great virtue in our culture, almost regardless of context. While some self-consciousness is inevitable in a complicated culture, high self-consciousness and low self-esteem go hand in hand.
A product of self-consciousness is frequent self-measurement, which impedes growth (usually the opposite of its intention) because it redoubles use of the will and muscular tension.
No one's self-awareness is perfect. Everyone can benefit from an occasional confrontation from others. A self-aware person will never be too surprised, because his or her self-perception will not have been too far off the mark. A self-conscious person is often hurt and surprised by these challenges and has difficulty incorporating the information.
Effective empathy requires self-awareness. Self-consciousness may produce solicitude toward other but contact and connection is poor because contact comes from the bodily effects others have on oneself. Mindfulness is a concept taken from Buddhism that is quite popular in psychology today. Clearly it is meant to denote self-awareness, but when approached as a moral or ethical precept will be often mistaken for self-consciousness. It is self-regulation and not self-consciousness that best underlies pro-social and loving behavior.
Beyond this many people are pre-occupied with ideas about what they believe they are, and what they believe they should be, how they should act and what they should do, and what they should have done to become what they believe they should be. They can discourse on this at length and in fine detail. This is self-absorption or perhaps more precisely, mind-absorption. Conversational therapies in which dis-embodied and ungrounded beliefs such as these are generated endlessly and explored exhaustively do not increase self-awareness.
There is an extreme state beyond self-consciousness when feeling is so low that the mind no longer recognizes the body when looking from the outside. This is depersonalization.
It is natural for thinking creatures to develop ideas about themselves. If these ideas are grounded in self-awareness and the truth of the body, then they will have a trueness to them and further life. If they are based on ego ideals, they will alienate one from his life and body.