The different stages of osteoporosis tell you how this bone disease progresses and weakens your bones as you age. It often presents no symptoms at all. It is frequently detected when you experience a fracture of the bone that can happen even with a mild injury.

Bone density is a measure of the amount of minerals (mostly calcium and phosphorous) present in a certain volume of your bone. It tells you how strong or weak your bones are. Bone density peaks at around the age of 30-35 years. In some individuals, it may peak earlier, at even 25 years.

As you age further, the bone density decreases, and your bones start becoming weaker. This process goes through progressive stages of osteoporosis. However, you must understand that this is a perfectly normal part of the aging process.

In this article, we are going to look at the early and advanced stages of osteoporosis, the symptoms of each stage, and the natural processes that govern bone density. This will help you understand the nature of the progression of this disease.

To fully understand the pathophysiology of osteoporosis, you have to know what are osteoblasts and osteoclasts.

The bone is a living tissue whose cells are constantly being broken down and replaced. The bone cells called osteocytes are of two types: osteoblasts and osteoclasts.

Osteoclasts are cells that break down and reabsorb bone tissue. Osteoblasts are cells that make new bone to replace the broken-down bone tissue. Both these cells work in a synchronized fashion to continually maintain bone strength as we age.

When you are young, your bones are growing and there is more bone tissue formation than there is bone loss. As you age there is a gradual reversal of this remodeling process.

Stages of osteoporosis

The stages of osteoporosis reveal to you how the biological processes that govern bone density progress as you age. Each stage from one to four exhibits the progressive loss of bone density and the increasing risk of fragility fractures.

The first stage of osteoporosis

When you are young, your bones grow faster than they break down. The first stage of osteoporosis is the stage when the rate of bone loss equals that of bone formation. The bone reabsorption and new bone formation reach a stage of balance.

This is the early beginning stage of osteoporosis and usually happens between the ages of 30 to 35 years (25-30 in some individuals). This stage presents no symptoms and your bone density scores (T-score) are normal and range from +1 to -1. This first stage of waning bone mineral density can be referred to as leaching.

The second stage of osteoporosis

In stage two, sometime between the age of 25 and 35 years, your bone loss is happening faster than your new bone can form.

Bone loss begins to occur at the rate of about 0.25% a year. This may vary and it depends on your genetic, environmental factors and dietary factors.

You will still not experience any symptoms, and your bone density scores may be anywhere from -1 to -2.5, indicating the presence of osteopenia, a predecessor to osteoporosis.

The third stage of osteoporosis

When your osteoporosis reaches stage three, typically between the ages of 45 to 55 years, your osteoporotic condition is now established. In this stage, the breakdown of your bone mass far exceeds the growth of new bone tissue, significantly increasing your risk and making you vulnerable to developing fractures.

This is particularly more so in women due to menopause and the decrease in the levels of the hormone, estrogen, which is essential in maintaining the health of all body tissues including bone, muscle, ligaments, and tendons.

Women may lose as much as 20% of their bone density during the five or so years after the onset of menopause. Some may lose even as much as 30%. It is quite common for women during menopause to lose 2% of bone mineral density

Men, too, lose bone density at around the age of 60 to 65 years when their testosterone levels decline.

You will not have any other symptoms except that of developing a fracture even with a mild trauma like hitting your legs against an object.

Stress on a bone that was earlier considered normal in younger years may now be enough to cause a fracture. Instances like tripping over an object, banging against a door, running, or even bending forward to pick up a heavy object can cause a stress fracture on your bone that is experiencing the biggest brunt.

In this stage, if you are tested, your bone density (T-score) will be -2.5 or lower. This third stage formally defines osteoporosis.

With this score, if you also suffer from poor balance along with significant loss of muscle mass and strength, the risk of falling and sustaining a fracture rises very high.

It is estimated that one in three women worldwide older than 50 years of age will experience a fracture due to osteoporosis. In men, however, it is estimated that one in five within the same age group will experience an osteoporosis-related fracture.

The fourth stage of osteoporosis

If not treated, your osteoporosis reaches stage four. In this stage, your osteoporosis is of the most severe degree. Your risk of fractures is very high much more than in stage three due to severe bone loss.

The complications of severe bone loss become visible. You will actually experience symptoms. Due to the severe bone loss in this stage, changes occur in your spine.

Your spinal bones become soft and weak, there is anterior wedging of the vertebral bones of the spine leading to deformities such as a stooped or bent-over posture called kyphosis due to the weakness of your bones in the spine. You lose a height of as much as two inches.

There is pain with everyday routine activities. It becomes more and more difficult to carry on routine activities such as getting in and out of a car, getting up from a chair or bed, climbing the stairs, etc.

You are very likely to have one or more fractures when you’ve entered stage four. In this stage, your T-score is well below -2.5.

To sum up:

Several stages of osteoporosis are defined. The first two stages are more like precursors to the actual disease and have no symptoms or signs. You will not notice anything abnormal.

The latter two stages define osteoporosis and you may suffer from frequent fractures, pain, or even bony deformities.