What Is Osteoporosis (Bone Loss)?

What it is

Although it looks static from the outside, bone is a living tissue that renews itself continuously. In this lifelong process, cells that remove old bone work alongside cells that build new bone. Formation and breakdown stay in balance in youth; bone mass reaches its highest level, known as peak bone mass, towards the end of the twenties. In later years breakdown slowly takes the lead and bone density gradually falls.

Osteoporosis is the state in which this decline becomes marked: bone mass falls and the fine honeycomb-like structure inside the bone becomes sparse. The result is a loss of strength and a bone that breaks easily. The common name "bone loss" is in a sense misleading: bone does not dissolve, its pores widen and its walls become thinner.

When bone density is below the average of a healthy young adult but has not yet reached the threshold for osteoporosis, the finding is called osteopenia. Osteopenia is not a disease but an intermediate step, and on its own it does not mean a fracture will occur; it is, however, taken as a signal for follow-up and for attention to daily habits.

Why it develops and who is affected

Osteoporosis does not have a single cause; it arises as several factors build up over the years. These factors are usually grouped under three headings.

Factors that cannot be changed. Advancing age, female sex, the menopause, a family history of hip fracture, a slight build and low body weight belong here. In women the fall in oestrogen after the menopause accelerates bone loss, and the rate of loss rises noticeably in the first years. Osteoporosis also occurs in men, usually appearing at a later age.

Factors related to daily habits. A sedentary life, smoking, heavy alcohol consumption, prolonged poor nutrition and being severely underweight are topics whose relationship with bone health has been studied. Bone is a tissue that grows stronger under the load placed on it; prolonged bed rest or inactivity speeds up loss.

Secondary causes. Other conditions and treatments also affect bone density: long term use of corticosteroids, disorders of the thyroid and parathyroid glands, rheumatic diseases, absorption disorders such as coeliac disease, chronic kidney and liver disease, an early menopause or removal of the ovaries, and low testosterone in men. You can ask your doctor how the medicines you take regularly relate to bone health; do not stop any medicine on your own decision.

Signs and a silent course

The most important feature of osteoporosis is that it progresses silently. A fall in bone density does not itself cause pain, which is why in many people the first sign is a fracture that follows a smaller strain than expected. A break that happens after a fall from standing height, and sometimes during coughing or lifting a heavy object, is called a fragility fracture.

Signs that may appear over time are:

• New pain in the back or lower back that does not settle fully with rest; vertebral compression fractures may be noticed this way.
• A loss of height; a loss reaching three or four centimetres over a few years is taken into account.
• Forward curving of the upper back and a change in posture.
• A reduced distance between the ribs and the hip bone, a protruding abdomen and a sense of breathlessness.

A large share of vertebral fractures pass unnoticed and are seen on an image taken for another reason. A hip fracture is the most serious, because of the loss of mobility and the long recovery it brings; prevention therefore comes before treatment.

Bone density measurement and diagnosis

Bone density is measured with a low dose X ray method called DXA. The examination is usually made at the lumbar spine and the hip, takes a few minutes, is painless and uses a low amount of radiation.

The result is reported with two scores. The T score compares the measured value with the average of a healthy young adult; this is the score used for diagnosis. The Z score compares the person with their own age group and is particularly useful in younger adults, in children and when a secondary cause is being sought. According to widely accepted thresholds, a T score of -1.0 or above is regarded as usual, a score between -1.0 and -2.5 is called osteopenia, and a score of -2.5 or below is called osteoporosis.

The decision is not made by looking at a number alone. Tools such as FRAX combine information including age, previous fracture, family history of hip fracture, smoking and corticosteroid use with bone density to estimate the risk of fracture over ten years. The doctor may also request blood and urine tests to look for secondary causes, and may add imaging of the spine where there is height loss or back pain. Screening such as heel ultrasound offered at shopping centres or fairs may give an impression, but it does not establish a diagnosis.

Who should be measured, and how often, varies from person to person; measurement usually comes up for women and men above a certain age, for those who have had a fragility fracture, for people using corticosteroids for a long period and for those carrying risk factors. This decision is made by your doctor.

Nutrition, activity and preventing falls

Calcium. It is the main building block of bone. Milk, yoghurt, cheese, dark green leafy vegetables, sesame and tahini, pulses and small fish eaten with their bones are the main sources. Daily requirement varies with age and circumstances; your own requirement is assessed by your doctor. Restricting calcium from food is generally not advised; those with a history of stones can find a fuller frame in our article on kidney stones.

Vitamin D. It plays a decisive part in the absorption of calcium from the intestine. It is produced in the body through the action of sunlight, and part of it comes from foods such as oily fish and eggs. Life spent indoors, style of dress, advanced age and the winter months reduce production; the level can be measured in a blood test. Whether your level needs to be measured, and what follows, is decided by your doctor.

Protein and other nutrients. Adequate protein intake is considered together with the preservation of bone and muscle mass. Vitamin K is a nutrient that plays a part in the functioning of certain proteins involved in bone formation, and research in this field continues. Magnesium, zinc and overall dietary balance are also examined under the heading of bone health. Before using any product it is sensible to consult your doctor or your pharmacist.

Activity. Bone grows stronger when load is placed on it. Brisk walking, climbing stairs, dancing and resistance work with light weights therefore come to the fore. Swimming and cycling are valuable for the heart and circulation, but as they do not load the bone they are not regarded as sufficient on their own. Balance work is aimed at reducing the risk of falling. In people who have had a vertebral fracture, movements involving bending forward and twisting the trunk need care; the programme should be set with the assessment of a doctor or physiotherapist.

Preventing falls. Most fractures follow a fall, so arrangements at home matter as much as treatment: securing loose rugs, fitting a grab rail in the bathroom, lighting corridors, tidying cables, wearing shoes with non-slip soles, having regular eye examinations and reviewing with the doctor any medicines that can cause dizziness. Stopping smoking and limiting alcohol are further steps that support bone health.

When to see a doctor

Seeing a doctor is appropriate in the following situations:

• A fracture after a minor strain or a fall from a low height.
• A loss of height of several centimetres, or marked curving of the back.
• New back pain that does not settle with rest and continues at night.
• A history of early menopause, removal of the ovaries or long standing menstrual irregularity.
• Use of corticosteroids for longer than three months, or a planned treatment that may affect bone health.
• A family history of hip fracture, particularly in a parent.
• Frequent falls, balance problems or dizziness.
• Complaints that can be confused with joint pain; for pain arising from the joints our article on osteoarthritis offers a separate frame.

In osteoporosis the treatment decision is made by weighing the bone density measurement, any history of fracture, the estimated fracture risk and the person's other conditions together; this assessment is made by a doctor. This page is intended as general information; for diagnosis and treatment consult your physician, and for questions about medicines consult your pharmacist.

Frequently asked questions

What is the difference between osteopenia and osteoporosis?

Both are defined by the value found on a bone density measurement. A T score between -1.0 and -2.5 is called osteopenia, and a score of -2.5 or below is called osteoporosis. Osteopenia is an intermediate step and does not on its own mean a fracture will occur; your doctor decides how it is followed up.

Does bone loss cause pain?

A fall in bone density does not itself cause pain, which is why osteoporosis often progresses silently. Pain usually appears when a fracture occurs, particularly with vertebral compression fractures. New back pain that does not settle calls for medical assessment.

Is a bone density scan harmful, and how often is it done?

The amount of radiation used in a DXA scan is low, and the examination takes a few minutes and is painless. Who is measured, and at what interval, depends on age, risk factors and the previous result; this decision is made by your doctor.

Does a calcium rich diet increase the risk of kidney stones?

Restricting calcium from food without reason is generally not advised. In people with a history of stones, diet, fluid intake and urine tests are assessed together; you can read our article on kidney stones for detail and discuss your own situation with your doctor.

Which kind of activity suits the bones?

Bone grows stronger when load is placed on it, so walking, climbing stairs and resistance work with light weights come to the fore. Balance work is aimed at reducing the risk of falling. Some movements need care in people who have had a vertebral fracture; the programme is set with the assessment of a doctor or physiotherapist.

Does osteoporosis occur only in women?

No. It is more common in women after the menopause, but it also occurs in men and is usually noticed at a later age. In men, low testosterone, long term corticosteroid use and chronic illnesses are the headings that stand out.

Aymed İlaç Sanayi manufactures authorised medicinal products in urology and nephrology. This page does not contain diagnostic or treatment advice; it is intended as general health information.