What is one of the common symptoms of osteoarthritis?

Pain in joints is a hallmark symptom of osteoarthritis, a degenerative joint disease characterized by the breakdown of cartilage in the joints. As the cartilage deteriorates, bones may begin to rub against each other, leading to pain, stiffness, and swelling in the affected areas. This pain is often exacerbated by movement and may improve with rest, making it a key indicator of osteoarthritis.

The other choices represent conditions or symptoms that are not associated with osteoarthritis. John's syndrome does not exist as a recognized medical condition, excessive bleeding is more related to issues with blood clotting or bleeding disorders, and porous bones are indicative of osteoporosis, a different condition. Therefore, pain in joints is indeed the most relevant and common symptom of osteoarthritis.