Symptoms of sacral osteoarthritis, also known as sacroiliitis, are characterized by pain, morning stiffness, and other symptoms. 1. Pain. Inflammation of the joints can lead to pain in the sacroiliac joints, which manifests as a dull, insidious pain that can radiate to the lower extremities. The pain worsens after activity and is relieved at rest. With the aggravation of the disease, the degree of pain also increases, often at night. 2. Morning stiffness. Stiffness of the joints is obvious, often in the morning when waking up. The stiffness is relieved by movement. As the disease worsens, the morning stiffness becomes more and more serious. 3. Other symptoms. With the aggravation of sacral osteoarthritis, joint instability, contracture of the surrounding muscles, and even joint deformity and other dysfunctions may occur. When symptoms appear and sacral osteoarthritis is suspected, it is necessary to consult the doctor as soon as possible and get timely treatment.