disc is a rubber like structure between two vertebral bones.  when it gets pressed and gets displaced back into spinal canal, it is called slip disc ie, displaced disc.

prevention and treatment is by avoiding bending and lifting weights and consult a doctor.

rest, painkiller tablets, electrolytes, painkiller ointment, stretching the muscle

consult a doctor

there are many causes. hypertension, hypoglycemia, anaemia, eye problems, etc. better show to doctor and get investigated especially if it is persisting.