Only one in every 20 people worldwide had no health problems in 2013, a major new analysis has revealed.

According to the findings, the vast majority of people worldwide were affected by some sort of health problem in 2013, with one-third of the global population - that is 2.3 billion people - experiencing more than five ailments.

The results are based on a detailed analysis of the Global Burden of Disease Study 2013, which included over 35,000 sources of information on disease and injury from 188 countries between 1990 and 2013.

The US researchers found that over the last 23 years, the leading causes of health problems have not changed significantly. They measured these in terms of ‘years lived with disability' (YLD), which is considered to be time spent in less than optimum health.

The biggest contributors to YLD were low back pain, depression, iron-deficiency anaemia, neck pain and age-related hearing loss.

In 2013, musculoskeletal disorders, such as low back pain and arthritis, along with mental and substance abuse disorders, such as depression, anxiety and alcohol abuse, were responsible for almost half of all health problems globally.

In fact in 2013, low back pain and major depression were among the top 10 greatest contributors to disability in every country worldwide, causing more health problems than asthma, diabetes and chronic obstructive pulmonary disease (COPD) combined.

The analysis found that eight chronic disorders affected more than 10% of the entire world's population. These included cavities in permanent teeth, which affected 2.4 billion people, tension headaches (1.6 billion), age-related hearing loss (1.23 billion) and iron-deficiency anaemia (1.2 billion).

It also noted a significant increase in health problems associated with diabetes (up 136%), Alzheimer's disease (up 92%) and osteoarthritis (up 75%).

The researchers highlighted the fact that rates of conditions and their related disabilities are declining significantly more slowly than death rates. For example, while rates of diabetes have risen by some 43% over the last 23 years, death rates have only increased by 9%.

"The fact that mortality is declining faster than non-fatal disease and injury prevalence is further evidence of the importance of paying attention to the rising health loss from these leading causes of disability, and not simply focusing on reducing mortality," commented the study's lead author, Prof Theo Vos, of the University of Washington.

He warned that as people are now living longer and the elderly population is increasing, the number of people living with poorer health is set to jump in the coming decades.

He insisted that major preventable causes of death, such as mental disorders and musculoskeletal disorders ‘have not received the attention that they deserve'.

"Addressing these issues will require a shift in health priorities around the world, not just to keep people alive into old age, but also to keep them healthy," he added.

Details of these findings are published in the medical journal, The Lancet.

For more information on depression, see our Depression Clinic here