Osteoporosis is a condition that affects the bones, causing them to become weak and fragile and more likely to break (fracture). These fractures most commonly occur in the spine, wrist and hips but can affect other bones such as the arm or pelvis.

Approximately 3 million people in the UK are thought to have osteoporosis, and there are over 230,000 fractures every year as a result. Although commonly associated with post-menopausal women, osteoporosis can also affect men, younger women and children.

Bone is made of a hard outer shell with a mesh of collagen (tough elastic fibres), minerals (including calcium), blood vessels and bone marrow inside. This mesh looks a bit like a honeycomb, with spaces between the different parts. Healthy bones are very dense, and the spaces inside the bones are small. In bone affected by osteoporosis, the spaces are larger, and this makes the bones weaker, less elastic and more likely to break

Bone is a living tissue that is constantly repairing itself. This process is called bone turnover. There are cells which break down old bone (osteoclasts) and cells which build new bone (osteoblasts). This process requires a range of proteins and minerals, which are absorbed from the bloodstream.

In childhood, bones grow and repair very quickly, but this process slows down as you get older. Bones stop growing in length between the ages of 16 and 18, but continue to increase in density until you are in your late 20s. From about the age of 35, you gradually lose bone density. This is a normal part of ageing, but for some people it can lead to osteoporosis and an increased risk of fractures.

Osteoporosis develops slowly over several years. It is likely that there will be no warning symptoms before a minor fall or sudden impact causes a bone fracture. Healthy bones should be able to withstand a fall from standing height, so a bone that breaks in these circumstances is known as a fragility fracture.

When the bones are significantly weakened (a low bone mass), breakages of the wrist, hip or spinal bones (vertebrae) are most common. A cough or a sneeze may cause the fracture of a rib or the partial collapse of one of the bones of the spine.

A fractured bone in an older person can be serious, depending on where it occurs. It may lead to long-term disability. For example, a hip fracture may lead to long-term problems with mobility.

One visible sign of osteoporosis is the characteristic stooping (bent forward) position that occurs in older people. It happens when the bones in the spine are fractured, making it difficult to support the weight of the body.

Is osteoporosis painful?

Osteoporosis usually doesn't cause pain unless a bone is broken as a result of the condition. Although not always painful, spinal fractures are the most common cause of chronic pain associated with the condition. 

Want to know more?

• Common Health Questions: how do I know if I’ve broken a bone?

How does osteoporosis develop?

Bones are at their thickest and strongest in early adult life and are constantly renewed and repaired through a process called bone turnover. However, as you age, this process is no longer balanced and bone loss increases. This means that bone is very slowly broken down over time, leading to a decrease in bone density as you get older. This can cause the bone to become weaker and increase your risk of breaking a bone.

Want to know more?

• National Osteoporosis Society: what is osteoporosis?
• National Osteoporosis Society: introduction to osteoporosis (PDF, 757kb)

Who is at risk of osteoporosis?

Osteoporosis can affect men and women. It is more common in older people, but it can affect younger people too.

Women

Women are at greater risk of developing osteoporosis than men. This is because changes in hormone levels can affect bone density. The female hormone oestrogen is essential for healthy bones. After the menopause, the level of oestrogen in the body falls, and this can lead to a rapid decrease in bone density. Women are at an even greater risk of developing osteoporosis when:

• they have an early menopause (before the age of 45)
• they have a hysterectomy before the age of 45, particularly when the ovaries are also removed
• their periods are absent for a long time (more than six months) as a result of over-exercising or over-dieting

Men

For most men who develop osteoporosis, the cause is unknown. However, one particular cause of osteoporosis is linked to the male hormone testosterone, which helps to keep the bones healthy. Men continue to produce this hormone into old age, but the risk of osteoporosis is increased in individuals with low levels of testosterone.

Diseases of the hormone-producing glands

Many hormones in the body can affect the process of bone turnover. If you have a disease of the hormone-producing glands, you may be at higher risk of developing osteoporosis. Osteoporosis can be triggered by hormone-related diseases, including:

• hyperthyroidism (overactive thyroid gland)
• disorders of the adrenal glands, such as Cushing's syndrome
• reduced output of sex hormones (oestrogen and testosterone)
• disorders of the pituitary gland

Other factors

Other factors that can increase the risk of osteoporosis and broken bones include:

• a family history of osteoporosis
• a parental history of hip fracture 
• a low body mass index (BMI of 19kg/m² or less)
• long-term use of high-dose corticosteroid treatment (widely used for conditions such as arthritis and asthma), which can affect bone strength
• heavy drinking and smoking
• rheumatoid arthritis 
• malabsorption problems, as experienced in coeliac disease and Crohn's disease
• some drugs used in breast cancer and prostate cancer treatment which affect hormone levels
• long periods of inactivity, such as long-term bed rest

Want to know more?

• National Osteoporosis Society: who is at risk of osteoporosis and broken bones?
• National Osteoporosis Society: osteoporosis and men (PDF, 203kb)

You may be diagnosed with osteoporosis if you have been identified as being at high risk and your GP has referred you for a bone density scan, known as a  DEXA scan.

Osteoporosis is often diagnosed after the weakening of the bones has led to a fracture. An X-ray is not a reliable method of measuring bone density but it is a useful way of identifying fractures.

DEXA scan

A DEXA (dual energy X-ray absorptiometry) scan can help diagnose osteoporosis.

It measures your bone mineral density (BMD) and compares it to the bone density of a healthy young adult and someone who is of the same age and sex as you.

The difference between your BMD measurement and that of a healthy young adult is calculated as a standard deviation (SD) and called a T score. Standard deviation is a measure of variability based on an average or expected value. A T score of:

• above -1 is normal 
• between -1 and -2.5 is classed as osteopenia (where bone density is lower than average but not low enough to be classed as osteoporosis)
• below -2.5 is classed as osteoporosis

A bone density scan can help to diagnose osteoporosis, but your BMD result is not the only factor that determines your risk of fracturing a bone.

Your doctor will also consider other relevant factors, such as your age, sex and any previous injuries that you have had before deciding whether you need to have treatment for osteoporosis.

If you need to have treatment, your doctor will suggest a treatment plan that is likely to be the safest and most effective for you.

Find out more about:

• DEXA scan
• National Osteoporosis Society: Scans and tests and osteoporosis (PDF, 347kb)

Being diagnosed with low bone density

If you are diagnosed with low bone mineral density, it may not necessarily mean that you have a high risk of fracture.

You should talk to your doctor about all of your risk factors for osteoporosis and broken bones. They can help you to take positive steps to improve your bone health.

Your genes determine your potential height and the strength of your skeleton. However, lifestyle factors such as diet and exercise can influence how healthy your bones are. Following a healthy lifestyle throughout your life is the best way to delay the onset of osteoporosis and slow the rate at which your bones become fragile.

Regular exercise

Regular exercise is essential. Adults should do at least 150 minutes (2 hours and 30 minutes) of moderate-intensity aerobic activity (i.e. cycling or fast walking) every week. Weight-bearing exercise and resistance exercise are particularly important in improving bone density and helping prevent osteoporosis.

If you’ve been diagnosed with osteoporosis, it’s a good idea to talk to your GP or health specialist before you take up any new exercise activity, to make sure it’s right for you.

Weight-bearing exercises

Weight-bearing exercises are exercises where your feet and legs support your weight. High-impact weight-bearing exercises, such as running, skipping, dancing, aerobics and even jumping up and down on the spot, are all useful ways to strengthen your muscles, ligaments and joints. When exercising, wear footwear that provides your ankles and feet with adequate support, such as trainers or walking boots.

People over the age of 60 can also benefit from doing regular weight-bearing exercise. This can include brisk walking, keep-fit classes or a game of tennis. Swimming and cycling are not weight-bearing exercises.

Resistance exercises

Resistance exercises are exercises that use muscle strength, where the action of the tendons pulling on the bones boosts bone strength. Examples include press-ups, weight lifting or using weight equipment at a gym. If you have recently joined a gym or you have not been for a while, your gym will probably offer you an induction. This involves being shown how to use all the equipment and recommended exercise techniques. If you are unsure how to use a piece of equipment or how to do an exercise, ask a gym instructor for help.

Healthy eating

Eating a healthy, balanced diet is recommended for everyone. It can help prevent many conditions, including heart disease, diabetes and many forms of cancer, as well as osteoporosis.

Calcium is very important for maintaining strong bones. The recommended intake of calcium is at least 700mg a day. This is about equivalent to one pint of milk. Calcium can also be found in a number of different foods, including green leafy vegetables, dried fruit, tofu and yoghurt.

Vitamin D is also important for bones and teeth as it helps your body to absorb calcium. Vitamin D can be found in eggs, milk and oily fish. However, most vitamin D is made in the skin in response to sunlight. A short exposure to sunlight, without sunscreen (10 minutes twice a day) throughout the summer should provide you with enough vitamin D for the whole year.

Certain groups of people may be at risk of not getting enough vitamin D. These include people who may be housebound or particularly frail, people with a poor diet, people who keep covered up in the sunshine because they wear total sun block or adhere to a certain dress code, and women who are pregnant or breastfeeding. If you are at risk of not getting enough vitamin D through your diet or lifestyle, you can take a vitamin D supplement. For adults, 10 micrograms a day of vitamin D is recommended. The recommended amount for children is 7 micrograms for babies under six months, and 8.5 micrograms for children aged six months to three years. Talk to your GP for more information.

Other factors

Other lifestyle factors that can help prevent osteoporosis include:

• quitting smoking: cigarette smoking is associated with an increased risk of osteoporosis
• limiting your alcohol intake: the recommended daily limit is three to four units of alcohol for men and two to three units for women

Want to know more?

• National Osteoporosis Society: healthy bones
• Birth to five: vitamins
• Food Standards Agency: vitamin D  

Dorothy Borbas was diagnosed with osteoporosis at 75 years of age.

“I discovered that I had osteoporosis in 1999, three days after I turned 75. I was in bed and had a cramp in my leg. When I got out of bed to stop the cramping, I fell and fractured two vertebrae. Before my fractures, I didn't realise that I had osteoporosis. It was some time before I received a firm diagnosis from the hospital. I then sought the help of the National Osteoporosis Society (NOS). 

“The NOS provided me with an absolute lifeline. I was able to speak at length with a nurse who put my mind at ease and gave me detailed information on diet, exercise and treatments.

“I joined my local NOS support group. I am now an active member and enjoy helping to organise local fundraising activities.”

Phyllis Long, aged 60, was recently diagnosed with osteoporosis after months of experiencing upper back pain

“I had severe pain in the right side of my upper back for about one month, and decided I needed to see my GP. My back was so sore when anything touched it that even lying in bed was uncomfortable. It felt like my very bones were sore.

“I went to see my GP in January and he wondered if I was experiencing thinning of my bones because of my age and my medical history. I’d had a few breakages in the past 10 years. He referred me to a consultant orthopaedic and spine surgeon, and he prescribed diclofenac painkillers to keep the pain at bay.

“The consultant suggested I have an MRI scan on my back and a bone density scan on my back and hips, which would measure the calcium in my bones. The MRI showed that I had arthritis in my lower three vertebrae, and the bone density scan gave me my T score. I was told that the T score baseline was 0 and that a score between 1 and 3 would be ‘normal’. Unfortunately, the scan revealed that my hips, at -1.3, were in the osteopenic level, and my spine, at -3, was in the osteoporotic level.

“The score meant that I definitely had osteoporosis, and that my back was worse than my hips. My doctor indicated that the emergency hysterectomy I had after the birth of my second child could have been a factor in developing osteoporosis. I was very taken aback. I'd led a healthy life, eating lots of fresh fruit and taking plenty of exercise. Plus, there was no history of osteoporosis in my family.

“My consultant told me that they would treat the condition with a tablet, called alendronic acid, which I now have to take once a week for the rest of my life. It’s from a group of non-hormonal medicines, known as bisphosphonates, which prevent bone loss from the body.

“I walk regularly and am active in the garden. The medical advice was to continue all activity as normal, as exercise would help increase the amount of calcium in my bones.

“I had to provide a list of the foods I regularly ate, so the doctor could see if there were any gaps in my diet. As I don’t have a very large intake of calcium, the doctor also prescribed chewable calcium tablets for me to take daily. I was given a list of high-calcium content foods, such as yoghurt, semi-skimmed milk, cheeses, whitebait, sardines and spinach, which I was advised to eat to boost my calcium intake.

“Within 24 months, I'll have another bone scan and my doctor is confident that my bone density will have increased significantly. For now, I'm waiting for an appointment with a rheumatologist, who I assume will help me further in dealing with the condition.”