Around 6.7 million people are living with undiagnosed hearing problems that could easily be addressed, says Action on Hearing Loss (http://www.actiononhearingloss.org.uk/).
While most of us would be quick to book an eye test if our sight began to deteriorate, it takes an average 10 years for people to tackle their hearing issues. However, that simple 20-minute check can hold the key to boosting your health and wellbeing in so many ways.
You're probably already aware that regular eye tests can help identify the early signs of diabetes. But did you know there's also significant, but often overlooked, evidence to suggest hearing checks play an equally vital role in diabetes diagnosis and care?
Hearing loss is around twice as common in adults with diabetes, according to a 2008 study funded by the National Institute of Health. And researchers at Henry Ford Hospital in the US found that women aged 60 to 75 with well-controlled diabetes had better hearing than those whose diabetes was poorly controlled. The reason? One theory is that high blood sugar levels may damage the delicate blood vessels and nerves in the inner ear.
Related: What you need to know about type 2 diabetes
2. Heart disease
Research has identified a significant link between hearing and heart health. 'The inner ear is so sensitive to blood flow, it's possible that abnormalities in the cardiovascular system could be noted here earlier than in other less sensitive parts of the body,' explains Dr David F Friedland, professor and vice-chair of otolaryngology and communication sciences at the Medical College of Wisconsin in the US.
In particular, Dr Friedland's research suggests that people with low-frequency hearing loss – that's the kind caused by damage to the inner ear hair cells – should be seen to be at risk of cardiovascular disease, so appropriate preventative measures are taken.
Related: What you need to know about cardiovascular disease
3. Kidney disease
Older adults with moderate chronic kidney disease (CKD) have a higher prevalence of hearing loss, according to an Australian study published in the American Journal of Kidney Diseases.
'The link can be explained by structural and functional similarities between tissues in the inner ear and in the kidney,' says the study's author Professor David Harris. 'Additionally, toxins that accumulate in kidney failure can damage nerves, including those in the inner ear.'
4. Depression and social isolation
It stands to reason that untreated hearing loss can lead to communication problems, low mood and anxiety – and there's plenty of research to back this up.
In fact, adults with hearing loss who don't wear aids are 50 per cent more likely to experience sadness or depression than those who do wear them, according to a study from the National Council on Aging in the US.
“Poor hearing can lead to all sorts of communication issues,” says Barry Downes, audiologist and Professional Services Manager for Amplifon. “If you’re struggling with background noise in an exercise class or group session you used to enjoy, you start to avoid it, and that can have an impact on your physical fitness as well as reducing the mental stimulation you get from mixing with other people.”
Related: Is it time for a hearing test?
5. Cognitive decline
Various studies have linked hearing loss to cognitive decline – and even dementia. While the exact reason is still unknown, experts believe it may be due to inflammation or social isolation, or a combination of the two.
However, wearing hearing aids can significantly slow this decline, according to a recent study published in the American Journal of Epidemiology.
Related: What you need to know about inflammation
6. Sleep apnoea
Obstructive sleep apnoea is a chronic condition where the walls of the throat relax and narrow during sleep, interrupting normal breathing.
People with sleep apnoea may be at increased risk of hearing loss, according to a 2014 study presented at the American Thoracic Society International Conference.
More research is needed into the exact causes – but lead author Dr Amit Chopra suggests the link may be a result of reduced blood supply to the inner ear or noise trauma from snoring.
Related: Dealing with sleep apnoea
7. General health and hospitalisation
Older adults with hearing loss are 32 per cent more likely to have been admitted to hospital and 36 per cent more likely to have suffered prolonged stretches of illness or injury, according to a study at the Johns Hopkins University School of Medicine in the US.
The study's authors believe this physical and mental decline may be due to the social isolation resulting from hearing loss. If hearing problems are addressed as early and effectively as possible, however, people are more likely to experience an improvement in their overall health.
Related: Nine surprising ways to prevent hearing loss