It was a scary experience...seeing a friend shaking like crazy and I can't do a thing about it. A colleague of mine said her slipped disk attacked and I don't know a thing about it except that it might have hurt like crazy cause she was shivering, had a high fever, and can't sit straight. We had to call an ambulance over and they transferred her on a stretcher to bring her in.

And because I am a curious little rabbit... I researched on what the heck slipped disk was about...

Slipped disk or spinal disc herniation (prolapsus disci intervertebralis) is a medical condition affecting the spine, in which a tear in the outer, fibrous ring (annulus fibrosus) of an intervertebral disc (discus intervertebralis) allows the soft, central portion (nucleus pulposus) to bulge out. Tears are almost always postero-lateral in nature owing to the presence of the posterior longitudinal ligament in the spinal canal. This tear in the disc ring may result in the release of inflammatory chemical mediators which may directly cause severe pain, even in the absence of nerve root compression. This is the rationale for the use of anti-inflammatory treatments for pain associated with disc herniation, protrusion, bulge, or disc tear.

It is normally a further development of a previously existing disc protrusion, a condition in which the outermost layers of the annulus fibrosus are still intact, but can bulge when the disc is under pressure. (SOURCE+CREDITS: Wikipedia)

Just the meaning of the sickness hurts my head T.T but its not what worried me but the causes of the sickness.. Still according to the same source...

Disc herniations can result from general wear and tear, such as when performing jobs that require constant sitting. However, herniations often result from jobs that require lifting. Traumatic (quick) injury to lumbar discs commonly occurs when lifting while bent at the waist, rather than lifting with the legs while the back is straight. Minor back pain and chronic back tiredness are indicators of general wear and tear that make one susceptible to herniation on the occurrence of a traumatic event, such as bending to pick up a pencil or falling. When the spine is straight, such as in standing or lying down, internal pressure is equalized on all parts of the discs.

Seeing my friend in pain makes me think twice about my posture... heck, if I would go through that pain just because I'm slouching or I rarely stand up... I'd freaking dance an hour more everyday and drink more milk.