Intervertebral disk is a cartilaginous layer between vertebrae. Disks provide mobility of bond of vertebrae and shock absorption. At some diseases the intervertebral disk is displaced. Slipped disk is also considered an intervertebral hernia.
The main reason of intervertebral hernia is osteochondrosis. Disks become thinner, lose flexibility, the content of water in them decreases. The thinned cartilage is more sensitive to influences; the disk can slip even at small loads. Besides weight lifting, the abrupt movements, jerks, vibration, falling, long sitting can become a starting factor. The probability of developing of disk hernias grows with age, at physical work, excessive body weight.
Rachiocampsis also leads to formation of disk hernias. Tuberculosis, trauma or tumor of backbone can be complicated by hernia.
More often hernias are formed in lumbar department. The loin experiences the greatest loading. Disk hernias develop in the neck because of large volume and complexity of movements.
At small expression of hernia there are pains owing to irritation of nervous roots. Further slipping, usually in the back direction, to the spinal channel, causes a persistent pain syndrome. The jelly-like core of disk can flow out completely out of limits of the broken-off connective tissue capsule, and connection between vertebrae loses flexibility.
At first in lumbar department pain is local. At abrupt intervertebral disk slipping the lumbago (lumbago) is possible. Further nervous roots are involved and pain becomes more intensive, extends along sciatic nerve in breech, femurs, sheens, feet. Sensitivity in feet decreases, movements are limited.