One insidious thing about osteoporosis is that it is a "silent" disease – there are no noticeable symptoms in most people with the disease, especially in the first years. There is no pain, no swelling, no change in how the patient looks or feels. The first visible symptom might be a bone fracture or a visible loss in height, by which time the osteoporosis is well along. That’s one reason older people should have periodic bone density tests.
Osteoporosis is also a slow-developing disease. It takes years for bone density to drop to a level for osteoporosis to be pronounced. A recent analysis found it takes an average of 17 years for people with median bone density values to transition to osteoporosis and 5 years for those with moderate osteopenia. Averages should be taken with a grain of salt and it should be remembered that everyone's bodies are different.
In the advanced stages, symptoms can include pain and literal disfigurement. It is not an easy pain to treat. Don’t think aspirin or ibuprofen can relieve this type of pain. The disfigurement can mean the person’s body looks different. Kyphosis, aka dowager’s hump, is when the osteoporosis patient’s spine curves and compresses so much there is a loss in height. It is not always painful (sometimes not painful at all), but it tells observers the person has osteoporosis.
Minor fractures might not be painful either, and the sufferer might not know a fracture has occurred without an x-ray. The minor fractures add up after a while and may cause pain, and can also increase the risk of major fractures. Stress fractures in osteoporosis patients are often caused by what might seem like trivial sources of stress. Walking or stepping down one step can trigger a stress fracture in someone with weak bones. The most common fractures occur in the wrist, hip, and spine.
When fractures occur in the spine, the pain is often severe and feels to the patient like radiating pain from the middle of the body to the sides. Loose teeth can be a sign of osteoporosis, too. You hear a lot about older people having broken hips. Often it isn’t the hip per se that breaks but the femur high up near the hip. Most people who break hips have weakened bones. Sometimes they get a broken hip as a result of a fall; other times the bone breaks because of some very trivial stress (e.g. stepping down from a small step) and the resulting break causes the person to fall down.
Because we have better methods today. Old fashioned X-ray imaging is okay for some medical procedure and analyses, but it does not have the sensitivity to be useful in determining bone thinning. Radiologists have found bones must lose over 30% of mass before the demineralization is evident on a plain film x-ray.
Our bones are constantly remodeled throughout life. The hard mineral matter is broken down by cells called osteoclasts and then built back up by other cells called osteoblasts. This remodeling process is important for healing microscopic fractures that occur during daily activities. Unfortunately the activity of osteoblasts slows down as we age while osteoclasts keep eating away at bone at a fairly steady rate. Over time, this results in low bone density. More on the pathogenesis of osteoporosis.
As bone loss increases with age, the steady process of remodeling, or bone turnover, removes bone more than it replaces. Remodeling involves two distinct stages: (1) bone resorption or bone formation, and (2) bone formation.
As men and women approach age 35, bone breakdown exceeds bone build up and bone density starts to decline.
A study of trends found that hip fractures among Americans increased from the mid-80s to the mid-90s and then declined to the mid 2000s. The mortality rate from hip fractures also decreased during the same period.