Light Pollution
Human beings can't stop evolving. We are programmed for that. Living without tech is an anathema to most of us. Well, thanks to the misuse of this technology, the natural sleeping cycle has been altered.
Nocturnal does not necessarily mean dark anymore. We have lit the streets of our towns; our homes and workplaces are filled with LED bulbs, televisions, smartphones, you can name it. The blue light emitted by these devices is a threat to falling asleep, because the suprachiasmatic nucleus does not readily release melatonin (sleep hormone) under this condition.
Caffeine
Caffeine is the most traded commodity in the world after oil. Well, if it was only that, it would be great. But that's not all, there is a lurking part of the transaction that lies far beneath the surface: you are trading your lifespan too.
People consume caffeine related goods like coca-cola or coffee for multiple reasons. This is what happens when they do so:
Caffeine sits at the entrance of the thalamus and clots there. Thereby preventing the adenosine accumulated—which continues to accumulate—the whole day to produce the sleep urge (adenosine can only be disposed through sleeping). Also, it makes the thalamus oblivious to the melatonin produced at your normal sleeping time so you'll not feel sleepy. Caffeine has a half-life of about 6 hours, and paired to that is its resistance to disposal by enzymes. As a result, the effects of an average dose of caffeine in-take can last up to 10 hours. However, sleeping before 2am is not in your plans and you decide to have some coffee.
Firstly, you have difficulties falling asleep—some might even think they are insomniac, if they even know what it means.
Secondly, you succeed falling asleep but you get a low-quality sleep and consequently can't fully enjoy the benefits of sleep (sustained immunity, memorizing, etc).
Finally, you wake up drowsy and your day is a mess in terms of concentration, happiness, and efficiency. Hence, you teeter between awakeness and sleep, or maybe not; you think you have a wonderful idea: taking another cup of coffee. That's the beginning of a negative cycle and eventually addiction.
Puberty ft society
As if puberty was not special enough with pimples, the circadian rhythm (internal clock), shifts the time at which teens sleep by about 2-3 hrs later. As such they hardly feel sleepy before 11pm, but most of them have to wake up before 6am due to early school starting time and sometimes parents. Consequently, they mostly sleep less than 6 hours and are deprived from the essential REM-phase (light-sleeping phase).
Some high schools which decided to push their starting times to 9:00am observed a significant increase (15%) in students' performance.
Procrastination
Procrastination is like falling the 1st domino of a series of negative events. One of those is sleep deprivation.
You have a task or tasks to complete in a given time interval. What commonly happens is that tasks are reported continuously till the deadline. You then want to eke out some time in order get things done. But there is a victim: your precious sleep.
Stress
Did you ever wonder why you find it hard to sleep when you lose money, have an important event the following day, or a relationship problem? The answer is simple and hormonal.
When you stress, adrenaline, cortisol, and noradrenaline are secreted. This noradrenaline—also called norepinephrine—eventually changes the chemical bath in your brain. As such, melatonin and adenosine can't function properly because the thalamus is sort of disabled. PTSD patients excessively secrete noradrenaline, as you can guess now, that's why they find it hard to sleep.
Alcohol and other sedatives
Yes, alcohol is a sedative, but a sedative hypnotic drug (acts as a central nervous system depressant at high doses). You might think that people who get drunk sleep easily and have a better sleep. This cannot be further from the truth.
Experiments showed that alcohol does not bring about anything positive as sleep is concerned. It rather jettisons the benefits one can inquire from sleep. In one of the experiments, two groups of undergraduates were asked to study after full nights, at least 8 hours, of sleep. The subjects were controlled the following days for them to get sufficient sleep. To one of the groups, moderate amounts of alcohol were given (about 2 glasses), 3 days after they studied. On the 5th day after they studied, both groups were tested. The sober group did not only outperformed the other fellows, but something particular was witnessed: alcohol does not just inhibits long term memory consolidation by damaging the hippocampus, but also erodes pre-existing memory.
Hence, if you have a test on Monday and you crammed your notes on the previous Wednesday, then resisted the temptation of a party for some days and succumbed on Saturday thinking that it was okay to have some drinks then...you should have just drank that same Wednesday, because you will mess up the test anyway.
Own your sleep elevate your life: solutions to sleep deprivation.