Bone is a living tissue that grows in a porous mesh-like structure. Throughout your life, your body breaks down old bone and rebuilds new bone in a continuous cycle. You gain bone by building more than you lose.
Bones contain the protein collagen and minerals, such as calcium and phosphorus, that make the collagen hard and dense.
To maintain bone density, your body needs adequate calcium and other minerals and certain levels of hormones, including oestrogen in women and testosterone in men.
Vitamin D is needed so your body can absorb calcium from food and incorporate it into your bones.
Physical activity (especially weight-bearing exercise) also helps your bones become dense.
Your bones grow more and more dense until around the age of 30. After about the age of 40, your bone breaks down slightly faster than it is replaced and your bones slowly become less dense.
Cause of thinning bones
Diet low in calcium and vitamin D
Having low intakes of calcium in your diet and not getting enough vitamin D (mainly from sunlight) puts people of all ages at risk of low bone density and poor bone health.
Lack of exercise
People who are inactive are also at risk, as weight-bearing physical activity (such as walking, dancing or jogging) helps bone become denser.
Reduced hormones (oestrogen and testosterone)
In women, the level of the hormone oestrogen decreases after menopause. Over many years, a low oestrogen level causes the inner mesh of bones to become thinner, weaker and more brittle.
In men, this can happen if there is too little testosterone.
The ongoing use of some medicines, including anticonvulsants or steroids such as prednisone.
One of the challenges with osteoporosis is that there are no early warning symptoms or signs. You may not know you have osteoporosis until you have one of the following:
A fracture of your wrist, hips, spine or other bones that happens more easily than it should, eg, after a slight bump or a simple fall. This type of fracture is also known as fragility fracture.
Loss of height – as the vertebrae of your spine weaken they compress and the spine curves.
With more severe osteoporosis, fractures that occur doing routine things like bending, lifting or just getting up from a chair. This happens because brittle bones have trouble supporting body weight.
Ask your doctor for an osteoporosis check if you experience the following:
fracture of the hip, wrist or spine for the first time
you are 50 years old or older and you have had a fracture
you have had a fracture that happened more easily than it should, eg, after a slight bump or a simple fall.
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Both men and women may have certain risk factors that can make them more likely to develop osteoporosis. Some of the risk factors that increase your likelihood of getting osteoporosis can't be changed, such as your gender or age, but many others can. See more at 'can osteoporosis be prevented?'
Risk factors for osteoporosis
Being female – women are at a greater risk of developing osteoporosis because of the rapid decline in oestrogen levels during menopause.
Increasing age – bones get thinner as you age.
A family history of osteoporosis or fractures.
Being very thin and unable to put on weight.
Drinking too much alcohol.
doing too little exercise.
Having low levels of calcium and vitamin D.
Long-term use of some medicines such as steroids, thyroxine, antiepileptic drugs, chemotherapy drugs or methotrexate.
In women, irregular periods or early menopause (before 45 years old, often caused by having your ovaries removed) can decrease oestrogen levels. In men, too little testosterone in conditions such as primary or secondary hypogonadism can also increase your risk.
Being immobilised in bed for long periods.
Some medical conditions such as rheumatoid arthritis, Crohn’s disease, coeliac disease, COPD, anorexia, hyperthyroidism or hyperparathyroidism.
Do men get osteoporosis?
Although osteoporosis is often considered to be a condition that only affects older women, men can get osteoporosis too. Men are most at risk of getting osteoporosis when their levels of testosterone decrease, such as with age or removal of the testes or because of medicines.
Can young people get osteoporosis?
Younger people can also be affected by osteoporosis. Younger women with eating disorders such as anorexiaor bulimia are at higher risk of developing osteoporosis, as are younger women who do so much exercise they stop having periods.
It's important to diagnose osteoporosis as the underlying cause if you get fractures easily, so you can get treated appropriately. If osteoporosis is left undiagnosed and untreated, it can cause complications. These include:
suffering from more fractures in the future
loss of independence
reduced quality of life
long-term nursing care
increased risk of death.
Your doctor can assess your risk for osteoporosis from your medical history and by asking you about your lifestyle. Physical signs that you may have weak bones include:
previous fractures (often of your wrist, hip or spine)
a loss of height or stooping
a curved spine.
Your doctor may suggest you have a bone density scan (also called a DEXA scan) to check for bone weakness. Blood tests may also be done to rule out causes such as any medical conditions that can cause osteoporosis.
Treatment for osteoporosis is decided on a case by case basis and depends on the results of bone density scans and other factors such as your age, gender, medical history and severity of the condition.
To help decide which treatment is suitable, you and your doctor may use a FRAX score or a Garvan score. This shows your risk of having a fracture due to osteoporosis in the next 10 years. Read more about osteoporosis tests.
Treatment most commonly involves lifestyle changes such as exercise and medicines that aim to increase bone density and reduce the risk of bone fracture. If you have a medical condition that causes your bones to be weak, treatment of the condition is also be needed.
Exercise for osteoporosis
If you have already been diagnosed with osteoporosis, you need to include physical activity into your daily life. Apart from strengthening your bones, exercise may relieve pain, make everyday tasks easier to carry out and help maintain or improve your posture. The 3 types of activities most often recommended for people with osteoporosis are:
weight-bearing aerobic activities
You need to check with your health provider which of these exercises are suitable for you. The main thing is to find an activity that you enjoy and that works for you given your medical condition.
Type of exercise
This includes the use of free weights, weight machines, resistance bands or water exercises to strengthen your muscles and bones in your arms and upper spine. Strength training can work directly on your bones to slow mineral loss.
Weight-bearing aerobic activities
This involves doing aerobic exercise on your feet, with your bones supporting your weight. Examples include walking, dancing, low-impact aerobics and gardening. These types of exercise work directly on the bones in your legs, hips and lower spine to slow mineral loss.
These can help increase the mobility of your joints, another key component of overall fitness. Being able to bend, extend and rotate your joints helps you prevent muscle injury. Increased flexibility can also help improve your posture.
Read more below about other lifestyle changes to prevent osteoporosis or to take care of your bones.
Taking steps to keep your bones healthy and strong is the best way to prevent osteoporosis from developing.
Eat a diet rich in calcium and vitamin D
Most of your body’s calcium is found in your bones. Calcium combines with other minerals to form the hard crystals that give your bones their strength and structure. Bones act like a calcium bank. If you do not take in enough calcium from your diet to replace losses and maintain adequate levels in your blood, your body reacts by withdrawing calcium from your bone bank and depositing it into your blood. If your body withdraws more calcium than it deposits over a long period, your bone density (bone strength) gradually declines and you may be at risk of developing osteoporosis.Vitamin D helps your intestines absorb calcium into your blood, which delivers it to your bones, muscles and other body tissues.
The best way to increase your calcium is by eating a balanced, nutritious diet. This is better than taking supplements. Aim to get your calcium from foods such as low-fat dairy options. A 250ml glass of regular milk contains about 300mg of calcium, and there are also higher calcium versions available.
For non-dairy options, soy milk is usually fortified with calcium – check the product label. Calcium is also found in other foods, eg, dark green leafy vegetables, almonds, sardines, salmon with bones and tofu. Read more about calcium.
Exercise is an important way to protect your bones. It can help preserve the bone strength you have and it improves coordination and balance, which can prevent falls that can lead to fractures. While some aerobic exercises such as swimming and cycling are great for your health, they aren’t that beneficial for building bone density.
The activities that really help build and strengthen bone are the weight-bearing kind, which force you to put weight on your muscles and bones. These include gardening, stair climbing, tennis, walking, weight lifting, tai chi, aerobics and dancing. These activities require your muscles to work against gravity. Read more about exercise.
Quit smoking and limit alcohol intake
Smokers tend to lose bone faster than non-smokers. Smoking may both interfere with the absorption of calcium and lower the amount of bone-protective oestrogen your body produces.
Similarly, drinking too much alcohol can cause bone loss and broken bones. Alcohol may interfere with your body’s ability to convert inactive vitamin D into its active form. It also appears to affect bone formation and increase losses of calcium and magnesium from your body. Excessive drinking may be accompanied by poor nutrition and an increased risk of falls. People who have more than 2 drinks per day may be at moderately higher risk of low bone density and fractures than non-drinkers.
Discover more about how to prevent osteoporosis in the video below. This video may take a few moments to load.
(Osteoporosis NZ, 2010)
A fall at any age can be dangerous but falls become increasingly common and far more likely to cause injury after the age of 55 years. If you have osteoporosis, you are more likely to break a bone if you fall, and if you do you might need a long time to recover.
Learning how to prevent falls can help you avoid broken bones and the problems they can cause.
In 2007, the Mayo Clinic developed the Osteoporosis Choicedecision aids. They are a helpful tool to use with patients to discuss the pros and cons of treatment and are based on using an estimate of the patient’s risk of bone fracture(external link) from the World Health Organization Collaborating Centre for Metabolic Bone Diseases, University of Sheffield, UK.
Osteoporosis update – Ian Reid(external link) Goodfellow Unit, 2017 Distinguished Professor Ian Reid talks about Osteoporosis New Zealand's guidance on diagnosing and managing osteoporosis in New Zealand. He is a professor of medicine and endocrinology at the University of Auckland and an international expert and research award winner in osteoporosis.