In the early stages of osteoporosis, the spongy tissue on the inside of the bone begins to break down making the bones more porous. Over time, the fine structures of the bones start to become brittle and more susceptible to breaking. As the disease progresses, vertebra in the spine may fracture and initially not cause any problems, and the person may be unaware of the break. These breaks often result in the stooped posture called dowager’s hump. During later stages of osteoporosis, bones can become so weak they break while lifting something as common as a full shopping bag, or just while stumbling.