Unable to get proper sleep at night? Blame that sleep tracking app, as a new study has revealed that wearable sleep tracking devices such as Fitbit or Apple Watch, designed to help people track sleep, may actually be keeping people awake.

The findings showed that when it comes to sleep, that enthusiasm for the devices may overshadow what they can deliver.

"It's great that so many people want to improve their sleep. However, the claims of these devices really outweigh validation of what they have shown to be doing. They don't do a good job of estimating sleep accurately," said lead author Kelly Glazer Baron, psychologist at Rush University in Illinois, US.

People tend to get so worried about whether or not they were getting enough shut-eye each night that the stress and anxiety keeps them awake. This may cause them 'orthosomnia' -- an unhealthy preoccupation with achieving perfect sleep, the researchers said.

People pursuing the quantified self rely on the daily acquisition of data to enhance their mental and physical life. But, some people do take it too far and that can be stressful, Baron said.

In addition, the sleep monitoring data on these devices can also be misleading as these popular devices are unable to accurately discriminate stages of sleep, the researchers emphasised in the Journal of Clinical Sleep Medicine.

"They are not able to differentiate between light and deep sleep. Furthermore, they might call it sleep when you're reading in bed," Baron explained.

On the other hand, these sleep-tracking devices, if used properly can be helpful, especially for those suffering with sleep apnea -- a serious sleep disorder -- the researchers said, while working toward finding better ways to incorporate them into the standard techniques of sleep therapy.