Smartphone addiction is affecting productivity, emotional well-being and relationships, a study of young Australians has found.

The Deakin University study of almost 400 undergraduate students found a third felt anxious if they were unable to regularly check their phones.

Forty per cent felt lost without it, 34 per cent lost sleep due to time spent on their devices and more than half were on their phones when they should be doing other things.

Fear of missing out, or FoMO, is one theory for why people can become overly reliant on their phones as they feel the need to constantly stay online and connected via social media.

Another major factor is the design of the phone and apps, which are "deliberately addictive" to entice users to stay on them as long as possible.

But Facebook and Instagram were only part of the story, with the study finding the mindless checking of smartphones out of habit rather than need, and entertainment use, such as watching videos or web browsing, was more closely linked to problematic use than using social media.

Now what has been formulated by researchers is probably self-evident for every teacher who has had to bark at students in class or every parent who cant even extract some paltry conversation at the dinner table. 

Worse still is this is an age group that is contemplating the responsibility of driving and taking their first tentative lessons toward that inherent risk. Having a compulsive urge to check that phone the moment it dings to them could be the greatest health hazard of all in coming life.

Schools of course have a number of rules about the devices not being in class and the police have certainly made clear the prohibition of mobile devices in traffic, but the broader question being posed here is around excess; too much of a good thing.

Some schools are taking the even more draconian step of sealing students phones to take away the temptation. The results should be intriguing.

Maybe it is not yet the widespread health issue many people fear but as with many health risks personality probably plays a key part in when just too much of that wonderful convenience is no longer a good thing.