No energy for anything: what to do when you're running on empty

Why "I Have No Energy" Is a Symptom, Not a Diagnosis

Fatigue is one of the most common symptoms in the world. A meta-analysis of 91 studies covering more than 620,000 people found that one adult in five lives with general fatigue, and one in ten with chronic fatigue lasting longer than six months. Yet fatigue on its own points to no particular illness: behind it can sit an iron deficiency, a thyroid problem, burnout or depression. So the question "what do I do when I have no energy" always starts with a different question: where exactly is the energy leaking?

Picture a phone that has started dying by lunchtime. There are two possible reasons, and they are fundamentally different. Either some app is eating the charge in the background, or the battery itself is worn out.

In the first case, you find the greedy app and close it. In the second, no settings will help: the battery has to be replaced. The body works the same way: first you establish whether it's an app or the hardware, and only then do you fix it.

Before you read on, take a reading. Rate your charge right now on a scale from 0 to 10, where 10 is "I could move mountains" and 0 is "I can't get off the sofa." Remember the number, and note what it was this morning. That gap will matter later: the way your charge behaves over the course of a day is one of the biggest clues to the cause.

When the Body Takes the Energy: Medical Causes of Fatigue

The most common medical causes of low energy are iron-deficiency anaemia and hidden iron deficiency, an underactive thyroid, low vitamin D, sleep disorders (including apnoea, or pauses in breathing during sleep), the after-effects of infections, and the side effects of certain medications. They all share one feature: rest does not fix them. You can sleep ten hours and still wake up wrecked, because your cells are literally short on oxygen or hormones. This whole list is checked with one basic panel: a complete blood count, ferritin, TSH and vitamin D (25-OH).

This is the "worn-out battery" scenario. And it is far more common than people assume.

Vitamin D is no better: almost half the people on the planet have levels below 50 nmol/L. Weakness and reduced muscle tone are among the consequences of that deficiency.

The thyroid is a story of its own. In hypothyroidism it produces fewer hormones than the body needs, and the entire metabolism slows down: you feel cold, gain weight, think less clearly and want to sleep all the time. A single TSH test rules that suspicion in or out.

When the Mind Takes the Energy: Burnout, Apathy and Depression

If the work-up finds nothing and you still have no energy, the likely cause is psychological. In ICD-11, the WHO's International Classification of Diseases, burnout is described as a syndrome with three components: feelings of exhaustion, growing mental distance from one's job or cynicism towards it, and reduced professional efficacy. Apathy and a loss of pleasure in the things that used to feel good, lasting longer than two weeks, are also a reason to check for depression: it drains energy even when every lab value is perfect.

Back to the phone. Here the battery is fine, but a dozen heavy apps are running around the clock in the background: deadlines, conflicts, anxiety, caring for other people, late-night message threads. Each one is bearable on its own. Together they eat the charge faster than it can be replenished.

How do you tell burnout from depression? The main marker is scope. Burnout is tied to one specific area: work wrings you dry, but seeing friends or going away on holiday still feels good. Depression is total: everything goes grey, including the parts of life that have nothing to do with your workload.

The test is no substitute for a diagnosis, but it points you in the right direction. And in both cases there is good news: these are conditions psychotherapy works with predictably and successfully.

What to Do When You Have No Energy: A Plan for Week One

The plan for low energy looks like this. Book an appointment with a physician and get the basic tests (complete blood count, ferritin, TSH, vitamin D); for one week, strip everything non-essential out of your schedule; restore the three foundations: 7–9 hours of sleep at the same time each night, regular meals, and 20–30 minutes of movement a day; and keep a short energy diary. If your charge hasn't started coming back in two or three weeks, bring in a psychologist or psychotherapist, because there is no point in waiting any longer.

The "strip out the non-essential" part is not about lying down and suffering. It is diagnostics: while the schedule is packed, there is no way to tell how much energy you actually have. Close the background apps for at least a week and watch what the charge does.

An energy diary is the simplest tool there is. Tonight, write down three things: which task took the most out of you, which one unexpectedly gave you energy, and your charge on that same scale from 0 to 10. After a week of entries you will see what isn't visible from the inside: fatigue has a structure, and it will tell you what to cut and what to add.

And about getting help. If you feel you can't work this out on your own, reach out to a psychologist or psychotherapist. Support now also comes in the form of AI: services like this run on clinical protocols and let you start right now, with no appointment and no waiting. That matters most at the stage where you don't even have the energy to go looking for a specialist.

Try Mira

Articles help you understand where energy leaks in general. But your battery is a specific one, with its own set of background apps, and it is better sorted out in a conversation than against a generic template.

Today an AI can hold that conversation. Mira is an AI designed for mental health that runs full therapeutic sessions on clinical protocols, including methods with proven effectiveness for burnout and apathy. Not a bot with canned replies, but a system built under the guidance of practicing psychotherapists: it works out which technique fits you, runs the session from start to finish, and remembers the context between sessions.

The biggest advantage of the format is that you can start right now, even if the only energy you have left is enough for typing: no appointment, no waiting, nowhere to travel.

Author

Mikhail Kumov

Psychotherapist, Clinical Director at Mira

Practicing psychotherapist with 25 years of clinical experience. Member of the Professional Psychotherapy League. Specializes in anxiety disorders, panic attacks, depression, burnout, and relationship difficulties. He led the development of the therapeutic protocols powering Mira AI.

Article reviewed against evidence-based psychotherapy protocolsLast reviewed: August 26, 2026Mira's evidence-based approach