Hair growing in a dream usually reflects returning vitality -- energy, confidence, or self-expression coming back after a period where it felt diminished. Thick, fast-growing hair can point to a renewed sense of identity, a visible sign that something in you is regenerating rather than fading away.
The infortunes in the eighth house have their malice increased; but the benevolents being there, portend neither good nor evil. - William Lilly (1602.-1681.)