There are several reasons for the swelling of the left hand: first, cervical spondylosis, when cervical spondylosis compresses the nerves, it can lead to disorders of the vegetative nerves and poor venous return, which can lead to swelling of the hand, then we should check cervical spine X-ray and MRI for early diagnosis. Second, venous thrombosis of the upper limbs, when there is venous thrombosis and venous blockage in the upper limbs, there can be poor venous return and lead to hand swelling symptoms, then early examination of vascular ultrasound to diagnose. Third, rheumatism and rheumatoid diseases, rheumatism and rheumatoid diseases can also lead to hand and finger swelling, pain, and limited activities, which should be diagnosed and treated by early blood tests and hand x-ray.