Take a group of five people. One of them will be suffering from chronic pain.
This is the sobering statistic about the most distressing symptom of illness and one of the major health problems of our time.
The personal suffering and cost is bad enough but chronic pain also costs the Australian economy more than $35 billion every year.
Professor Eric Visser, the inaugural Churack chair of Chronic Pain Education and Research at the University of Notre Dame in Fremantle, said pain was an unmet area of need in health care. 
"It is a silent epidemic," he said. "Pain in children is even more under-recognised ... and up to 10 per cent of children and teenagers have chronic pain." 
Professor Visser said most chronic pain was musculoskeletal, with back pain being number one, followed by neck pain and whiplash, and then arthritis, particularly in the knee and hip.
Obesity was another cause of musculoskeletal pain and weight loss and a healthy diet were very important in pain management. 
Professor Visser, a specialist pain medicine physician and anaesthesiologist and a clinical senior lecturer at the University of Western Australia, said workplace injuries were a big problem and could be life-altering.
Cancer pain was also common and management was shared with palliative-care specialists.
Chronic pain could also be neuropathic in origin, relating to nerve damage, and was usually from an injury, or after an operation, shingles, a stroke or spinal cord damage and was often missed. 
Headache pain was common and 5 per cent of the population had severe headaches every day of the week. 
"But if you take too much pain medication, it can make your headache worse," Professor Visser said. "Medication-overuse headache is a big pain problem. Even if you take a few simple over-the-counter pain medications for a few weeks for headache, it changes the chemistry of the brain and makes your headache worse. Then it becomes a vicious cycle."
Professor Visser said 10 per cent of people taking prescription opioid medicines became addicted. Over-the-counter medicines, including anti-inflammatories and codeine-based drugs, were even more of a problem and could be quite dangerous.
"They are mainly designed to be used for a few days for an acute pain problem but if people are using them every day for chronic pain, that is really quite dangerous," he said. "They produce the medication-use headaches and if people overuse them they can get stomach ulcers, kidney failure and heart attacks." 
Some people also over-used alcohol or drugs, particularly marijuana, to cope. 
Disabling pain could impact on quality of life and income. Significant depression or anxiety disorder were common, affecting at least 80 per cent of people with chronic pain compared with 15 per cent of the general population. 
Management was holistic and included medical and other therapies as well as psychological, social and spiritual aspects, he said.
"Very often it is the social worker or the psychologist or the physiotherapist who does more things than the pain specialist with their needles and drugs in managing pain," he said.
"So for a headache, for instance, you would try to manage the primary headache, like the migraine, as best you can and then give them other strategies to deal with the headaches rather than tablets or medication," he said. 
"These strategies can include relaxation, meditation, mindfulness, physical therapies such as exercise and stretches, and lifestyle changes such as stress management and posture.'
Professor Visser said his group would co-ordinate pain research in areas as diverse as acupuncture, molecular science, indigenous health and spiritual aspects of pain. The aim was to translate findings into practical care as soon as possible.
"There's a lot of misinformation about pain in the community, including among doctors, and certainly on the internet," he said. "This may lead to poor pain diagnosis and treatment and disappointment, frustrations and false hope for persons seeking management of their chronic pain."
It is an inconvenient truth that in some cases, chronic pain may not be able to be cured. 
"We have to give people realistic information and realistic expectations," Professor Visser said. "The absolute miracle pain cure is more the exception than the rule. But we can certainly offer good hope and management."
'Pain in children is even more under-recognised ... and up to 10 per cent of children and teenagers
 have chronic pain.'
Eric Visser 
1.  Prevent workplace injuries to the back and spine.
2.  Avoid being overweight or obese. This can cause musculoskeletal pain and can also lead to diabetes, which can result in nerve pain.
3.  Get acute pain treated immediately.
4.  If chronic pain develops, seek treatment early.
Source: Professor Eric Visser