Etrog (Citron) corresponds to the three sefirot of conscious emotion in the heart, which are Generosity ( Chesed ), Discipline ( Gevurah ), and Beauty (Tiferet )*, and so it inherits the following attributes:

Body: Left shoulder, arm, and hand.
Kabbalistic Attribute : Boundary-setting, form-building, self-preserving force in the universe.

Emotional Expression : Discipline, awe, caution, aversion.
Mental Expression : Critical discernment.
Spiritual Expression : Awe of God and fear of the consequences of wrong action.

Etrog's Healing Correspondences - Gevurah
(When combined with Barley)

Balanced, Rectified, God-Centered Expression: Discrimination in giving so that one doesn't feed the forces that oppose God and good. Acting from fear of estranging oneself from God.

When Contaminated by Serpent (Ego) Consciousness: Selfish, miserly, unwilling to share one's resources with others. Acting from fear of social disapproval.

Pathological Expression: Avoidant Personality Disorder where the force of constriction and withdrawal is so overbalanced that it becomes crippling. ( Avoidant Personality Disorder is defined as a pervasive pattern of social inhibition, feelings of inadequacy, and hypersensitivity to negative evaluation.)

Too Little on the...

Emotional Plane: No boundaries, always merging. Can't say no, but can't live up to commitments. Feeling resentful for giving too much.

Mental Plane: Always deciding that the next step in personal and spiritual development requires more self-constriction (rather than, perhaps, sometimes, the loosening of reins). Conservative to the point of strangling all growth.

Mental Plane: Lacking self-criticism. Impulsive.

Spiritual Plane: Fear-based relationship with God and religious practice, where one's primary motivation is the avoidance of “punishment.” Overly stringent.

Spiritual Plane: Insufficient drive and discipline to push beyond one's current comfort zone and to sustain a path of growth.