Why Am I Always Tired and Have No Energy?

clinician image
Medically approved by Dr Earim Chaudry
Chief Medical Officer
iconLast updated 7th January 2022
In 30 seconds…

“Why am I always tired and have no energy?” If you’ve had a busy week, you do a lot of physical activity, or you’ve got a new baby keeping you up at night, tiredness is something normal. But, if your tiredness is not relieved by sleep and rest, then you’re dealing with fatigue, which is a little different.

Fatigue is when your tiredness and low energy levels can feel overwhelming. And, from depression and anxiety to conditions including chronic fatigue syndrome and anaemia, there are many possible causes.

In most cases, though, low energy is caused by your habits and lifestyle choices. These can include excessive caffeine or alcohol consumption, or a poor diet. However, it is well worth finding out what is causing your symptoms – so that you can start feeling better again.

Sleep, Tiredness, and Low Energy

Sometimes a good night’s sleep just doesn’t cut it. Tiredness and a general feeling of low energy can linger into the next day, and the next, and the next. If you’re getting enough sleep but you still feel out of sorts, we call this fatigue – and there is probably an underlying cause.

“So, why am I always tired and have no energy?” There are lots of possible reasons. It could be something to do with your lifestyle, such as a prolonged period in which you are working – or partying – too hard. But it could be a physical cause, like an iron deficiency, or a mental health issue like depression or anxiety.

In this article, we’ll take a look at the reasons behind fatigue in more detail. And the good news is, there are ways to overcome it.

Common Symptoms of Fatigue

As we mentioned, tiredness and fatigue are a little different. If you’re tired on a Friday night after a hard week at work and you feel better on Saturday morning, that’s normal. But if you feel tired every day, you lack energy, and you can’t concentrate, you might just be experiencing fatigue.

Symptoms of fatigue include:

  • Daytime sleepiness
  • Headaches
  • Joint pain and muscles that feel weak, achy, or heavy
  • Irritability
  • Slower decision-making and reduced concentration
  • Low motivation

And, in really serious cases, you may experience reduced immune system function, weight loss, impaired memory, and hallucinations. Sleep is really crucial for the overall healthy functioning of your body, and many of your biological processes will suffer if your sleep quality suffers.

If you are experiencing fatigue or a lack of energy, it won’t be a mystery, however. You’ll recognise the symptoms – and, at their worst, they can be debilitating.

Why am I Always Tired and Have No Energy? Some Possible Causes

So, what is causing your fatigue? As we said, there are a number of possible reasons, and they’re not all about poor sleep or lack of sleep.

Rather, everything from lifestyle choices to underlying mental health issues can be responsible for changes in your energy levels. And, to treat the symptoms effectively, it’s vital that you correctly identify the cause.

Your Lifestyle

Let’s start with your lifestyle choices. These are often the most obvious causes of fatigue. While that might sound scary, it does mean that you have the power to cure your problem quite easily. Here are some common elements of your lifestyle that can affect your energy levels.

Excessive Alcohol Consumption

Alcohol is a depressant. It slows down your body and its processes and, as you’re probably aware, it makes you sleepy. However, while it might make it easier for you to drop off, it’s reducing the quality of your sleep in the long run – even if you’re still getting lots of hours in bed.

But it’s not just the heavy nights that make a difference. The effects of alcohol accumulate even if you drink just a little every day.

Too Much Caffeine

Caffeine, on the other hand, is a stimulant. You wake up, drink your coffee, and feel ready to start the day. However, when the caffeine wears off, you slump, and when you drink too much coffee, this slump gets more dramatic.

But that’s before you even consider the effect of caffeine on sleep. Caffeine makes it more difficult for you to get to sleep – and it’s more likely to result in interrupted sleep. Further, studies have shown that those who drink more coffee are more likely to wake up tired.


Regular exercise helps strengthen the health of your heart and cardiovascular system and boosts your mood, muscle strength, and overall wellness. However, too much exercise – or exercise without sufficient fuel, training, or recovery – can result in exhaustion.

Not enough exercise, though, is a more common cause of low energy. While it is not fully understood why, exercise increases your energy levels throughout the day.

Poor Diet

Your diet is your body’s source of energy. However, if your diet is poorly balanced, it can leave you feeling as though you’re lacking the fuel you need. Too much sugar is one problem, for example. Like caffeine, this can produce a rush of energy, followed by a slump.

A balanced diet should include a range of proteins, carbohydrates, and healthy fats. Don’t forget to include vitamins and minerals too.

It’s worth pointing out that a large proportion of people reporting low energy also experience symptoms of irritable bowel syndrome. As a result, it can be helpful to be aware of what you eat when tackling fatigue.

Psychological Causes

Let’s turn now to some possible psychological causes of fatigue. While, for some, ‘psychological’ can sound like ‘less important’ or ‘less real’, these causes are very concrete. A number of mental health conditions – such as depression and anxiety – can significantly affect your energy levels. And getting through them is not just a case of ‘manning up’.

Depression, for example, is the condition in which sufferers experience low mood, a lack of motivation, and a debilitating range of negative emotions. As many as 90% of people with depression experience fatigue. It can affect the quality of your sleep, and, unfortunately, antidepressants can too.

Anxiety – or generalised anxiety disorder – can also cause low energy and fatigue. Characterised by restlessness, worry, irritability, and difficulty concentrating, anxiety can result in dramatically fluctuating levels of energy, while negatively affect your sleep at the same time.

It’s best if you speak to someone if you feel like your low energy is due to mental health. Discuss it with someone you trust or book an appointment with a doctor.

Other Medical Conditions

Finally, there are other medical conditions that can affect your energy levels. These range from those that directly interrupt your sleep to those that lower your body’s ability to produce energy.

Despite the range of possible causes here, these are best treated with the support of a healthcare provider, who will be able to provide medical advice specific to your condition.

Anaemia (Anemia)

Perhaps the most common medical cause of fatigue, iron deficiency anaemia is a condition in which your body lacks sufficient iron.

While it’s most commonly experienced by women, anaemia can affect men too. And, with symptoms including heavy muscles, a lack of motivation, and becoming tired very easily, it can be draining.

Chronic Fatigue Syndrome (Myalgic Encephalomyelitis)

A poorly understood condition, chronic fatigue syndrome (or CFS, or ME) affects people’s motivation, their energy levels, and their ability to do physical exercise. Other symptoms include a general sense of being unwell.

It may be caused by your genes, mental health conditions, or other medical conditions such as glandular fever. It is most often experienced by people in their mid-twenties to mid-forties.

Sleep Apnoea

Sleep apnoea (or sleep apnea) is a condition in which, when sleeping, your throat closes and your breathing is interrupted. This means that your oxygen levels fall and you wake up during the night.

It is most common in men who are overweight, while alcohol and cigarettes make it worse. Sleeping on your side, however, can help – as can trying to lose weight.

Thyroid Problems

Thyroid problems are another common cause of fatigue. However, these have nothing to do with your sleep. Rather, when your thyroid gland is underactive, you produce too little of a hormone known as thyroxine, and this can make you feel tired.


Lastly, while not a medical condition, the medicines that treat some conditions can cause fatigue and low energy. We mentioned above, for example, that antidepressants can have this effect – but they are not the only ones.

Antihistamines can also make you drowsy, while anti-anxiety medications and blood pressure pills can have the same effect.

Key Takeaways

So, why are you always tired? There’s no one answer, unfortunately. From poor mental health to a range of physical medical conditions, there are many reasons why you might have low energy.

However, these are not always chronic health problems. Rather, many of the most common reasons for fatigue are the result of lifestyle choices. In this case, cutting down on alcohol and caffeine may well help make you feel better – while ensuring that you’re enjoying a balanced diet is crucial, too.


Rebecca L Orbeta, Mary D Overpeck, Darmendra Ramcharran, Michael D Kogan, Rebecca Ledsky (2006). High caffeine intake in adolescents: associations with difficulty sleeping and feeling tired in the morning:


Timothy W Puetz (2006). Physical activity and feelings of energy and fatigue: epidemiological evidence:


Dorottya Nagy-Szakal, Brent L. Williams, Nischay Mishra, Xiaoyu Che, Bohyun Lee, Lucinda Bateman, Nancy G. Klimas, Anthony L. Komaroff, Susan Levine, Jose G. Montoya, Daniel L. Peterson, Devi Ramanan, Komal Jain, Meredith L. Eddy, Mady Hornig & W. Ian Lipkin (2017). Fecal metagenomic profiles in subgroups of patients with myalgic encephalomyelitis/chronic fatigue syndrome:


Helia Ghanean, Amanda K. Ceniti & Sidney H. Kennedy (2018). Fatigue in Patients with Major Depressive Disorder: Prevalence, Burden and Pharmacological Approaches to Management:

While we've ensured that everything you read on the Health Centre is medically reviewed and approved, information presented here is not intended to be a substitute for professional medical advice, diagnosis, or treatment. It should never be relied upon for specific medical advice. If you have any questions or concerns, please talk to your doctor.

Your Guide to Using Promethazine for Sleep
Promethazine is a drowsy antihistamine that is proven to help insomnia.
When to Take CBD Oil for Sleep
The research is young, but CBD oil is showing some promising possibilities when it comes to alleviating the symptoms of sleep disorders.
What Over The Counter Sleeping Pills Can You Get in the UK?
There are two ways to get sleeping pills in the UK — by prescription or over the counter.
Your Guide to Sleep Inertia
Sleep inertia is the feeling of grogginess, drowsiness, or disorientation you feel immediately after you wake up.
We use cookies to analyse data and personalise your visit, learn more in our privacy policy