There may be the following causes of painful symptoms in the lower part of the waist: 1. The most common disease that can lead to painful symptoms in the waist is lumbar muscle strain, especially long-term chronic recurrent lumbar pain, and soft tissue injury in the waist is the most common. Lumbar muscle strain then belongs to the chronic lumbar muscle injury, prolonged sitting, bending labor or high-intensity sports training, etc., can lead to repeated minor injuries to the lumbar muscles, the previous injury has not healed, and a new injury has appeared. The accumulation of such injuries can lead to significant scarring of the local muscles. The larger the scar, the greater the irritation to the surrounding soft tissues, and the more severe the pain symptoms. Pain is more obvious after lumbar exertion, while patients with severe lumbar strain will experience painful symptoms at rest. 2. Lumbar spine diseases and inflammation of the soft tissues around the lumbar spine will also present painful symptoms in the location. For example, lumbar disc herniation, lumbar transverse synovial syndrome, etc. In addition to lumbar pain, this condition will also present painful numbness symptoms in the legs.