It is said that lying down for a practice yoga nidra can give the equivalent of up to 4 hours of sleep. This can be deeply restorative for those of us who struggle with insomnia, interrupted or poor quality night time sleep.
Regulate your nervous system
Having an over-worked nervous system can result in a prolonged state of anxiety and stress. When you slow down the sympathetic nervous system, which is responsible for the fight or flight response, the parasympathetic nervous system is then able to operate the rest + digest function, enabling the body to begin healing.  Yoga Nidra aids in working towards a healthy and responsive neural system that generates the appropriate response when needed.
A wonderful aspect of Yoga Nidra is calling in elevated emotions, expanding the heart's energetic field and creating opportunity for blissful relaxation. 
Support your healing
Entering the lower, slower brainwave states of alpha, delta, and theta has beautifully regenerative effects on our brains and bodies, both physically, mentally, and emotionally.