Calf joint pain is considered to be caused by long-term calf strain, lumbar intervertebral disc herniation, varicose veins in the calf and other reasons. 1. Long-term strain: weight-bearing walking, long-term stretching, marathon, etc. can cause chronic strain of calf muscles, joints, ligaments and other soft tissues, edema, congestion and other manifestations, which can result in calf joint pain, swelling, restricted movement and joint popping and other symptoms, and aggravation of pain when the activity is strenuous and weight-bearing. 2. Lumbar disc herniation: degenerative changes of lumbar intervertebral discs and secondary degenerative changes of intervertebral joints can stimulate and compress the nerve roots, causing pain in the lumbar back and radiating pain in the lower limbs, and there can be pain in the calf joints, numbness, weakness and other sensory and motor abnormalities. 3. Varicose veins of calf: due to the damage of the venous valve of the blood vessels in the calf area, it causes the obstruction of venous return, which is manifested as worm-like swelling of the veins, and pain, swelling and fatigue of the calf joints and muscles appear. Calf joint pain may also be caused by trauma, etc. It is recommended to consult a doctor for a clear diagnosis and targeted treatment under the doctor’s guidance.