You sit down to read, write or work, and your mind slides off the page. You reread the same line three times. You reach for your phone without deciding to. It feels like something in you has broken, or that you used to be sharper.
Probably nothing has broken. Focus is a skill that depends on conditions, and several of those conditions have likely shifted without you noticing. This covers the common causes, what the research says about each, and what tends to help.
What does it mean when you can't focus on anything?
Usually it means your attention is being pulled in more directions than it can hold, not that you have lost the ability to concentrate.
Attention seems to be tied to what you feed it. If your day is a stream of short, rapid inputs, a long, slow task may feel unusually hard by comparison. Research on short-form video and on heavy media multitasking shows associations with worse attention, though not that one causes the other. Either way, it is a mismatch between your recent habits and the task, not a character flaw.
It can also be a sign that you are tired, stressed or low, which are worth taking seriously on their own. If it is severe, new, or comes with other changes, talking to a doctor is a sensible step.
Is your phone the reason you can't focus?
It is a likely contributor, and the pull is not only notifications.
An observational study of real-life smartphone use found that most interactions, about 89%, were started by the user rather than prompted by a notification. So the interruptions are often coming from the reach, not the buzz.
Gloria Mark, who studies attention at UC Irvine, reports in her book Attention Span that in her recent studies the average time on a single screen before switching was about 47 seconds. Switching that often leaves little room for deep focus.
Source: Heitmayer & Lahlou (2021), Computers in Human Behavior, https://doi.org/10.1016/j.chb.2020.106637. Gloria Mark, Attention Span (2023).
Notifications do cost something too. One study found that social media notifications during a focus task caused a brief slowdown in processing, and the size of the effect tracked how many notifications people got and their checking habits rather than total screen time.
Even a phone you are not touching may matter. In one study, people did best on working-memory and fluid-intelligence tests with their phone in another room and worst with it on the desk, even when it was silenced. Later replications found smaller or mixed effects, so treat this as suggestive, not settled.
Source: Ward, Duke, Gneezy & Bos (2017), Journal of the Association for Consumer Research.
Can short-form video make it harder to concentrate?
The research points that way, though it is correlational.
A 2025 meta-analysis in Psychological Bulletin pooled 71 studies and about 98,299 people. Heavier short-form video use was linked to poorer attention and, most strongly, poorer inhibitory control, which is the ability to stop yourself doing the easy thing. It was also linked to more stress and anxiety.
That does not prove videos cause the problem. People who already struggle to focus may also watch more. But the pattern is consistent enough to be worth testing on yourself.
Source: Nguyen et al. (2025), Psychological Bulletin.
Does poor sleep cause lack of focus and concentration?
Sleep can plausibly play a part, and screens can feed into it.
A 2025 meta-analysis in Frontiers in Psychiatry pooled 21 cohort studies covering 548,338 people. Each extra hour of daily screen time was associated with a bedtime about 13.2 minutes later, roughly 3 to 5 minutes less sleep, and higher odds of difficulty falling asleep.
Those numbers look small, but they may add up night after night, and tired attention is poor attention. This can also form a loop: a worse day of focus often means more scrolling in the evening, which costs more sleep.
Source: He et al. (2025), Frontiers in Psychiatry.
Why can't I focus like I used to?
Part of the answer is that the conditions around you changed, even if you did not.
If you are asking why you can't focus anymore when you once could, look at what has changed in the last year or two. More hours on the phone, later nights, more feeds, more tabs, more stress. Any one is manageable. Together they stack.
Heavy media multitasking has been linked to worse performance on task-switching and filtering tests than light multitasking. That is an association, so it may run both ways, but it is consistent with the experience of struggling to stay on one thing.
Source: Ophir, Nass & Wagner (2009), PNAS.
Is it permanent?
One trial suggests it may not be.
In a randomised trial published in PNAS Nexus in 2025, 467 participants had mobile internet blocked on their smartphones for two weeks. Calls and texts still worked. The trial reported improvements in sustained attention, mental health and subjective well-being. The attention gain was comparable to about 10 years of age-related decline, and increased nightly sleep was one of the mechanisms.
So two weeks of changed conditions produced measurable change in that trial. Worth noting that the block was imposed by the study, which is different from relying on willpower each evening.
Source: Castelo et al. (2025), PNAS Nexus.
What helps when you can't focus lately?
None of this needs to be dramatic. A few changes, tried for a couple of weeks, will tell you more than any amount of worrying.
- Move the phone. Put it in another room while you do one task. It costs nothing and removes the reach.
- Cut the feed that hurts most. If short-form video is your main one, start there rather than with everything.
- Protect your bedtime. Screens later at night tend to push sleep later. Even a modest earlier cutoff helps the next day.
- Work in one block. Pick one task and a set time. Expect the first few minutes to feel restless. That passes.
- Give it two weeks. Judge the change over a fortnight, not a day. The early days can feel flatter before they feel better.
If you want help in the gap where you would normally reach, Boredom's Daily Reset gives you three guided minutes for it. It is optional, and the changes above work without it.
The short version
Trouble focusing is rarely one thing. A phone that keeps pulling you, short-form video habits, slipping sleep and general stress all stack, and the research links phone interruptions and short-form video use to worse attention.
One trial found that changing the conditions for two weeks improved attention. Change the conditions for a couple of weeks and see what comes back.