An elderly women slipped in the bathroom and had severe pain in her lower back. After X-ray examination doctors told her it is due to a slipped disc. What does that mean? How does it affect our health?

Slipped disc is a medical condition in which spine is affected due to wear and tear in the outer fibrous ring (anulus fibrous) of an intervertebral disc, allowing the soft, central portion to bulge out beyond the damaged outer rings.
These intervertebral disc are present between the bodies of adjacent vertebrae from the second cervical vertebra to the sacrum. This discs form strong joints that permit various movements of vertebral column and absorbs vertical shock. 

The cause of slip disc can be due to general wear and tear of intervertebral disc during performing various jobs, that require constant sitting and squatting. The slipped disc or herniation occurs in two regions of body, i.e., cervical disc and lumber disc. 
Slip disc in lower back lumber disc, lead to sharp pain in one part of leg due to sciatica, (disturbance in sciatic nerve), hip and cause numbness in other lower parts of the body. 
Slip disc in neck region (cervical disc) leads to pain while moving neck near or over the shoulder bone or pain occurs while moving forearm, or fingers. It also causes numbness in shoulder, elbow, forearm and finger area. 
Hence, slipped disc affect the upper and lower body parts, thus, influencing life style and health.