The herniated part of the disc can be resorbed by the inflammatory process, which means that inflammatory cells, such as macrophages, can remove the damaged tissue. The healing time can range from several weeks to months.
Conservatively treated massive prolapsed discs: a 7-year follow-up (The Royal College of Surgeons, 2010):
The mechanism by which herniated discs are resorbed is not fully
understood. It is generally thought that an immune response develops
to the disc tissue and inflammation helps to remove the invading
Massive disc herniations usually reduce in volume and by 6 months most
are only a third of their original size. Several studies have shown
that the largest discs appear to have the greatest tendency to resolve.
Long-Term Course to Lumbar Disc Resorption Patients and Predictive Factors Associated with Disc Resorption (Evidence-Based Complementary and Alternative Medicine, 2017):
Of 505 participants, 19 did not show disc resorption, while 486 did. A
total of 220 displayed resorption rates of ≥50%.
There is insufficient evidence that any treatment, including analgesics, physical therapy, spinal manipulation, steroid injections and surgery result in greater symptom relief 1-2 years after the onset of symptoms than no specific treatment at all (BMJ, 2007, European Spine Journal, 2007).
Early surgery should be considered when symptoms are unbearable, are bilateral, involve the perineum (the area between the legs) or bladder or bowel dysfunction (cauda equina syndrome).