Throughout our lives, however fit and well we may be, it’s almost guaranteed that we will still worry about our health from time to time.

And thankfully, due to huge technological and medical advancements, doctors are able to offer acute and highly sensitive screenings, scans and tests to pick up potential risks and diseases sometimes way ahead of the symptoms showing up.

[Read more: The 6 health screenings you should never ignore]

But how much is this preoccupation with predicting our medical futures actually helping us prevent, treat, and recover from health problems? And often do doctors over-diagnose patients, leaving them with treatment side-effects but no benefits?

Over-diagnosis

At 70 years old, doctor and TV presenter Michael Mosley’s father participated in a routine health assessment and was diagnosed as having a slow-growing tumour on his prostate.

[Read more: Everything you need to know about cervical cancer]

Dr Mosley recalls asking his father not to have surgery to remove the tumour on his prostate “as the chances were his heart disease would see him off long before the cancer could do its worst”.

However, his father couldn’t bear to live with the cancer and had surgery to remove the tumour, leaving him with the potentially avoidable side-effects of incontinence and impotence. Dr Mosley lost his father just two years later at the age of 72, “his life blighted by indignities” caused by surgery Dr Mosley was convinced was unnecessary.

In the BBC Horizon documentary series, Are Health Tests Really A Good Idea?, Dr Mosley puts himself through a battery of health tests, available to perfectly well people, to find out just how beneficial they are weighed against the potentially devastating consequences.

Availability

We spend £135m a year on private health tests and around £754m on NHS screenings. But if we feel healthy enough, are we right to poke, prod and explore our insides just to potentially find something wrong and avoid a serious illness spreading?

You can easily visit private or NHS doctors, or even buy your own home remedy kits to help detect potential health risks and diseases before symptoms occur.

The NHS provides both a Health Check service described as a ‘body ‘MOT’ and NHS Screenings to find out if people are at a higher risk of developing a health problem.

The NHS Health Check service is aimed at 40 to 74-year-olds and checks that some of your body’s most important systems are all running smoothly.

These services aim to check for:

• Heart disease
• Stroke
• Type 2 diabetes
• Kidney disease
• Some forms of dementia

Alongside these tests, an NHS Health Check will also measure:

• Blood pressure
• BMI
• Cholesterol levels

Meanwhile NHS Screenings cover:

• Pregnancy
• Newborn babies
• Cervical
• Breast
• Bowel Cancer
• Abdominal aortic aneurysm (AAA)

So how useful are health screenings?

Dr Anne Mackie, director of programmes at the NHS national screening committee, argues that while screening intuitively sounds like a good idea, “a lot of the tests aren’t that helpful”, and instead advises those considering private screening to check which “rigorously evaluated” tests are available on the NHS.

Which? group chief executive Peter Vicary-Smith confirmed this, saying: “As your GP may well have to carry out their own tests to confirm a positive diagnosis anyway, you may be better off saving your money and going straight to your GP.”

US urologist Professor Richard Ablin, who first researched and developed the PSA prostate test, said “the science was pushed too far” and that “people were too fast to biopsy, too fast to treat. In the U.S alone, some 60 billion dollars has been wasted on over-diagnosis and over-treatment.”

Pros of health screenings:

- NHS Health Checks save on average 650 lives per year
- Prevent hundreds of thousands of health problems developing
- Early screenings can make treatment more effective
- Helps people make more informed decisions about their health

Cons of health screenings:

- Early screenings can lead to over-diagnosis of a potentially harmless illness
- Can be misleading, inaccurate, expensive
- Confusing language in home kit diagnosis
- Can trigger false alarms or false reassurance
- Diagnosed with harmless strand of disease resulting in treatment side-effects but no benefits
- Increases anxiety