What is the principle that the condition of patients with lumbar disc herniation gets worse after catching cold?

It is generally believed that the pain of lumbar disc herniation is mainly related to the compression of nerve roots and the accumulation of local metabolites. When the bulging/protruding intervertebral disc component moves to a certain nerve root position of the lumbar spine, it can cause compression on the nerve root. Cold can reduce the circulation level of ligament and muscle tissue near the diseased intervertebral disc, which will bring two consequences: the elasticity and supporting force of ligament and muscle fiber tissue decrease, which is brilliantly summarized as "cold dominates attraction" in traditional Chinese medicine; The level of local circulation decreased and the accumulation of metabolites increased. The first situation will aggravate the compression of intervertebral disc, and then aggravate the compression of nerve roots. At this time, the acute radiation pain in the waist and lower limbs will be aggravated; In the second case, the accumulation of metabolites increases, which is manifested in low back pain.