Signs & Symptoms

The 15 Hidden Causes of Low Energy (Science-Backed)

Have you ever had days or maybe even weeks where you've felt worn out and you simply just didn't have the energy to go about your daily routine? Maybe this feeling comes and goes, or it can even persist and slowly start to interrupt your life.

Low energy or chronic fatigue can affect your emotional, physical and mental health. What's worse, everyday things can cause your low energy levels, and it may not have just one cause. You may find yourself having to go through a variety of tests and eliminating things to find the root cause of your low energy so you can treat it effectively. [1>

We understand how frustrating this can be, and this is why we've put together 15 common causes of low energy levels. You'll be able to go over them one by one and rule them out until you find out the reason behind your low energy levels. This will help you effectively treat and manage it, and this can help you lead a normal life.


15 Causes Of Low Energy

  1. Stress
  2. Leaky Gut Syndrome
  3. SIBO
  4. Fluctuating Blood Sugar Levels
  5. Not Getting Enough Sleep
  6. High Consumption of Coffee
  7. Poor Thyroid Function
  8. Dehydration and Not Drinking Enough Water
  9. Vitamin B12 Deficiency
  10. Iron Deficiency
  11. Anxiety and Depression
  12. Anemia
  13. Alcohol
  14. Sedentary Lifestyle
  15. Poor Diet

Bottom Line

15 Causes Of Low Energy

1. Stress

Did you know that stress can play a huge role in how well you feel or how much energy you have? In fact, stress can negatively impact both your physical and mental health. [2> When you have stress in your life, or when you feel stressed out in general, your body responds by flooding your body with cortisol and adrenaline. These are your fight-or-flight response hormones. [3>

When these hormones flood your body, your heartbeat starts to go faster, your muscles tense and your breathing speeds up. This is great in survival situations, but it's not so great when this flood of hormones has no release and they circulate around your body. [4>

For people with chronic stress, this can be a never-ending cycle that starts to quickly take a negative toll on your body. A study showed that constant stress has negative implications for your physical, behavioural and emotional health. [5> Researchers found that constant high levels of stress can make your body work harder to regulate itself, and this results in drained energy levels.

Another study found that over 2,000 people reported having less energy when they had higher levels of stress. [6> They found that the stress levels made it difficult to fall asleep and stay asleep, and this left the participants feeling drained and listless as they went about their day. The researchers found that people who had consistent high stress levels got less sleep and felt more restless the longer the exposure to stress went on. [7>

It also explains why most people have aches and pains along with no or low energy when they have stress. The high levels of tension don't allow you to relax, and your muscles can ache or you can feel sore.

2. Leaky Gut Syndrome

Leaky Gut Syndrome is a digestive tract issue where your intestinal lining gets inflamed and develops small fissures or cracks. When this happens, bacteria can make its way through your intestinal wall and into the rest of your body. Your immune system will respond with inflammation when it triggers that there is bacteria where it isn't supposed to be, and this can lead to system-wide inflammation. [8>

Also, with this inflammation comes elevated levels of cytokines. Cytokines control your cell's growth, development, migration and differentiation. [9> These proteins have a direct influence on regulating certain hormones throughout your body, and this means that they play a direct role in how fatigued you feel. [10> They're one of the main causes of chronic fatigue, and your fatigue can get worse depending on your levels of cytokines.

The worse your leaky gut gets and the more bacteria it releases into your system, the worse you're going to feel. One study showed that low energy levels and chronic fatigue tends to fluctuate and get worse with mental and physical exertion. [11> So, you may feel better for a short period of time, getup and do something mentally or physically challenging, and you'll be back to feeling like you have no energy.

Leaky gut can also cause your body to not be able to absorb all of the nutrients it needs to function because your intestines are unable to produce enough enzymes to break down the food you eat. This can lead to things like hormone imbalances, and researchers found that a hormone imbalance can also result in low energy levels. [12>


SIBO stands for Small Intestinal Bacterial Overgrowth, and this is a medical condition that doctors believe affect approximately 15% of the population. [13> If you have this condition, you have an extremely high level of bacteria present in your small intestine. You can experience all different forms of this conditions ranging from no symptoms and mild to very severe. Additionally, this condition can flare up and recede, and it has links to other intestinal issues like IBS. [14>

Although SIBO isn't widely understood, recent research shows that there are potential links betweenSIBO or a bacterial imbalance in your digestive system and low energy levels. Just like with leaky gut, this disruption in your intestinal tract can wreak havoc on your entire body, and one of the first signs is fatigue or low energy. [15>

Several studies show that SIBO can cause very poor nutrient absorption because it can directly affect how fast or slow food moves through your intestines. [16> It could potentially push food though at a very rapid rate, and this means that you won't get the full nutrients from your food, and you could end up lacking vitamin B12.

Vitamin B12 plays a vital role in helping to regulate the feeling of low energy. One study took 38participants who had low energy levels and chronic fatigue and began giving them shots of vitamin B12. They found that the participants who received the vitamin B12 reported feelings of more energy and less fatigue. <17>

SIBO can also cause your body to work overtime to try and regulate your body's bacteria levels, and this can result in feeling drained because your body will pull nutrients from other areas and put a greater strain on your body overall. [18>

4. Fluctuating Blood Sugar Levels

Your blood sugar or blood glucose refers to the amount of sugar that you find in your blood. You get this sugar from the foods you eat, and it's the main source of energy for your body. When you have a consistent blood sugar, you'll have consistent levels of energy without any huge highs or lows. [19>

When your blood sugar fluctuates, your body scrambles to try and regulate it. You can start to feel sick, nauseous, dizzy, faint or drained. These symptoms can get worse as your blood sugar spikes or drops to dangerous lows because your body will either try harder to pull sugar from your food, or it can also flood your system with hormones to try and get your blood sugar to safe and stable levels.

This low energy or fatigue is especially present in people who have Diabetes, and it's one of the hallmark symptoms of the condition. One 2015 study took 40 participants with Type 1 diabetes and found that the majority of them reported overwhelmingly low energy levels as their blood sugar levels peaked and dropped. [20>

For people who have blood sugar spikes, it makes it more difficult for your blood to flow throughout your system. This can result in reduced levels of oxygen that make it to your cells, and this results in lower energy levels or feeling sleepy. [21>

Low blood sugar and insulin resistance can slow your body down on a cellular level, and this makes your body pull sugar stores from other places in your body. It also brings on inflammation, and inflammation is what can make you feel exhausted or drained like you feel after you've had the flu.[22>

5. Not Getting Enough Sleep

Around one-third of adults in the United States report that they don't get enough sleep each night, and this difficulty falling asleep or staying asleep can cause problems throughout your body. [23> Not only can you have physical problems like slower reflexes and fatigue, but you can also have emotional problems like irritability, concentration difficulties and aches or pains.

When you don't get enough sleep because you have chronic levels of stress in your life, your levels of cortisol can increase. As we mentioned, this is one of the things responsible for the fight-or-flight response, and they can cause you to feel restless, have difficulty falling asleep and insomnia. [24>

Additionally, not getting enough sleep, a chemical called adenosine starts to build up in your brain. This chemical is responsible for the feeling of fatigue and it signals that we need to go to sleep. The longer you're awake, the more this chemical builds up, and it'll lead to you feeling like you have no energy to accomplish even the smallest of tasks. [25>

This chemical is why people who have problems sleeping tend to feel very drained or sleepy throughout the day. It gets worse as it builds up, and you can start feeling it when you miss as little as 1.5 hours of sleep. When you go to sleep, your body breaks down adnisone, and this is why you wakeup feeling refreshed.

If your low energy is directly caused by simply not getting enough sleep, you should start to feel better when you do catch up on your sleep. It may take a few days to completely feel better though.

6. High Consumption of Coffee

Coffee is one of the most popular beverages around the world, and millions of people enjoy at least one cup of coffee every day, if not more. Coffee contains caffeine, and this a natural stimulant in the coffee beans. The beans get roasted and ground before they're sold to the general public, and many people depend on this boost of caffeine each day to help them start their days and give them energy.

However, since the caffeine content in coffee is a stimulant, this can cause problems if you stop drinking it or significantly reduce your caffeine intake. Did you know that you can start to go through caffeine withdrawal relatively quickly? Caffeine withdrawals can lead to the feeling of low energy of fatigue because your body isn't getting the stimulant that it has become dependent on getting each day. [26>

Additionally, if you over consume coffee, you're loading your body with unhealthy amounts of caffeine, this can lead to low energy levels and chronic feelings of fatigue. There are dozens of studies that show that if you over-consume caffeine one day, you'll feel alert. However, you'll have lower energy levels the next day as your body starts to regulate itself again. [27>

Since this is a stimulant, it can interfere with your ability to fall asleep and stay asleep, especially if you drink it within a few hours of trying to fall asleep. This can lead to low energy levels that only get worse the longer you go trying to fix them by drinking coffee. One study showed that you should stop drinking coffee at least six hours before bed so you can fall asleep like you normally would. [28>

7. Poor Thyroid Function

Your thyroid gland is found in your throat, and the main role of your thyroid gland is to regulate your body's metabolic processes like growth and how quickly you go through your energy stores. [29> For people who have a normal functioning thyroid gland, they won't have any issues with their energy levels. However, when you start to have issues with your thyroid gland working properly, this is where you start to see flagging and low energy levels.

One of the most common problems with your thyroid that can cause low energy is called hypothyroidism. Hypothyroidism means that your thyroid gland is not working as well as it should and it's underactive. When your thyroid isn't as active as it should be, this leads to a drop in your thyroid's hormone levels. Your body uses these hormones to create and use energy, so you'll feel drained and fatigued if it's not working like it should.

A study explored how your thyroid gland works with the rest of your body, and they found that one of the main indicators of hypothyroidism is the feeling of fatigue. The processes in your body, such as energy production, will slow way down in response to low thyroid hormones. This can cause things like weight gain, low energy, mood swings and more. [30>

Also, if you have an overactive thyroid or hyperthyroidism, you can also feel fatigued. When you have this condition, your thyroid produces too many hormones, and this can leave you feeling anxious, restless and unable to sleep. Once it disrupts your sleep patterns, you'll start to experience low energy throughout the day. [31>

8. Dehydration and Not Drinking Enough Water

Water is important and essential for every system and function in your body, and you are made up of around 60% water. It acts as a building material at a cellular level, regulates your internal body temperature, transports carbohydrates and nutrients through your bloodstream, flushes waste from your system, lubricates your joints and acts like a shock absorber for your spinal cord and brain.

Dehydration occurs when you're not drinking enough water to support these functions in your body.You can lose water faster than you can replace it, especially if you're not drinking enough water in the first place. [32> Dehydration means that you don't have enough fluid in your body for your systems to function at their peak levels, and that you don't have enough electrolytes.

When you get dehydrated, your body's total blood volume drops. [33> Once this volume declines, your circulatory system has to work much harder to push oxygenated blood throughout your system and deliver it to your muscles, skin and brain.

This can force your bodily systems to slow down to accommodate the slower blood volume course throughout your body, and you'll start to notice flagging energy levels. As you get more and more dehydrated, you'll have less and less energy. Since most people are already slightly dehydrated, it's very easy to slip into a very dehydrated state. [34>

Drinking more water throughout the day can decrease your dehydration levels and give you more energy. Your body won't have to work as hard to perform the normal functions, and your cells will be able to create and store more energy for you to use throughout the day.

9. Vitamin B12 Deficiency

Vitamin B12 is an essential water-soluble vitamin that plays a critical role in your body's energy metabolism. It's a huge component of your endurance levels as well as an energy enhancement vitamin, and when you have good levels of this vitamin, you have more energy.

Since vitamin B12 plays a significant role in your body's energy production, having a deficiency can very quickly slow down your body's overall energy production levels. [35> This can cause your body to pull any energy you have stored in your cells, and you'll start to feel fatigued and have low energy levels as the day goes on.

This vitamin has a long use as a natural energy supplement, and having a vitamin B12 deficiency can cause low energy. One study took 40 patients who had recently suffered a stroke and split them intogroups. One group got a vitamin B12 supplement throughout the course of the study, and the control group got a placebo. At the end of the study, the group that got the vitamin B12 reported less fatigue and increased energy levels over the control group. [36>

Another study noted that a deficiency in vitamin B12 could lead to increased levels of anxiety or depression, and these two things can have a direct impact on your energy levels. Depression is well-known for causing low energy levels, and anxiety can prompt your body to release cortisol which can further influence your low energy levels. [37>

You don't store this vitamin in your cells, so a lot of it gets flushed out in your urine. Your body isn't able to absorb it quickly, and only a very small amount stays in your liver. A deficiency will pull these excess stores very quickly, and your body will have to work harder to support itself without vitaminB12. [38>

10. Iron Deficiency

Iron is a mineral that you can find in many different foods and dietary supplements. It's essential for the transfer of oxygen from your blood to your lungs and other tissues. Iron also helps with general growth, normal cellular functions, development, connective tissue growth and hormone production. [39>

If you have an iron deficiency, it means that you don't have high enough levels of iron in your body to support all of the functions that iron normally performs or helps with like we listed above. It's one of the most common deficiencies today, and children under 18 and pregnant women are the two groups who are most affected by it. [40>

People who have an iron deficiency usually report low energy levels, extreme fatigue or feeling exhausted. You feel like this because your body is having trouble carrying the oxygen from your blood to your cells, and this reduces your energy levels as a whole. One study showed that giving non-anemic women an iron supplement each day could increase their energy levels and reduce the amount of fatigue they felt. [41>

Another Australian study took a questionnaire and gave it to over 12,000 women over the span of two years. At first, many of the participants reported increased fatigue and low energy levels, but once they started taking an iron supplement to boost their natural iron levels, they reported two years later that they had more energy and they felt more alert throughout the day. [42>

11. Anxiety and Depression

Depression and anxiety are two huge mental health issues in the United States and around the world, with estimated millions of people having one or both of these conditions. [43> Depression results in the person feeling drained, fatigued, achy and as having low energy. Anxiety, on the other hand, can make someone feel excessively worried or anxious, nervous and eventually fatigued as their heightened state catches up with the energy reserves. [44>

The exact cause of depression isn't known, but it is widely believed to have something to do with your hormones. One of the most common symptoms with people suffering from depression is low energy levels or feeling mentally and physically exhausted. [45> These levels can fluctuate depending on whether or not your depression fluctuates. You may have days where you have more energy and days where you feel drained.

When you have anxiety, you can be in an almost constant state of worry or tension. This can cause your body to feel stressed on a constant basis, and your body will respond by flooding your systems with adrenal hormones because it thinks that you're in danger. This stress response can draw from your energy stores and leave you feeling drained with very low energy levels. [46>

One study compared the low energy levels you can feel with anxiety and stress side by side by studying twins. They found that the twin who reported being fatigued experienced higher levels of anxiety and depression than the twin who wasn't fatigued. [47>

12. Anemia

Hemoglobin is an iron-rich protein that you find in your blood. It helps carry oxygen in your red blood cells from your lungs and to your cells and the rest of your body. For people who are anemic, they don't have enough hemoglobin. You won't get enough oxygen-rich blood circulating throughout your body, and this can bring on feelings of weakness, tiredness and low energy levels. [48>

Anemia is extremely common, and mild anemia won't cause too many issues. However, when you get severely anemic, you'll start to notice flagging energy levels. These low energy levels occur when your systems and organs don't get enough oxygen to perform at their peak levels and do the jobs they have to do to keep you healthy. [49>

When you don't have enough iron in your blood, your levels of oxygen-rich blood decreases. This means that all of your systems have to start to work harder to produce adequate energy levels to support your everyday functions. If your body can't produce enough energy, it starts to take energy from any stores it may have. This is why you can feel more fatigued when you get up and do something. [50>

13. Alcohol

For many people, the belief that drinking alcohol will make them sleep better causes them to imbibe before bed. Unfortunately, alcohol doesn't help you sleep better, and it can actually interrupt your sleep and increase your feelings of low energy when you do wake up several hours later. [51>

The reason alcohol contributes to lower energy levels is because it acts like a stimulant a few hours after you digest it, and it prompts your body to release a stress hormone called epinephrine. This hormone actually stimulates your heart to beat faster and it stimulates your body in general. This can result in interrupted sleep patterns and waking up several times during the night. [52>

This disrupted sleep pattern can quickly influence how awake or sleepy you feel the next day, and you'll most likely spend at least one or two days recovering from it and feeling like you have very low energy. This is especially true if you use alcohol to sleep every night, and it can get markedly worse after three straight days of drinking before bed. [53>

Excessive alcohol intake can also cause dehydration, and this can have a direct effect on your energy levels. This will get more severe the longer you drink significant amounts of alcohol and neglect your water intake. [54> It can throw your electrolyte levels out of balance, and this contributes to the fatigued and drained feeling you experience directly after a day or night of heavy drinking that can take a few days without a drink to restore the balance.

The more you drink, the longer it can take for you to bring your body back to normal. This all has negative effects on your physical and mental energy levels.

14. Sedentary Lifestyle

When you lead a sedentary lifestyle, you're leading a lifestyle that involves very little amounts of physical exercise. You spend a lot of time sitting and lying around, and when you do get up for physical exercise, it's typically sporadic and very short-lived. [55> This type of lifestyle can contribute to several physical and mental health issues including weight gain, high blood pressure and low energy levels.

When you lead a sedentary lifestyle, you start to de-condition your musculoskeletal system as well as your cardiovascular system. This de-conditioning can depress your mood, which in turn may result in low energy levels and fatigue. Additionally, you'll start to lose your strength and your muscle mass if you don't use them. [56> Your muscle metabolism will start to change as well, and this can make it more difficult for you to change your sedentary lifestyle.

Several studies have highlighted how living a sedentary lifestyle has a negative impact on people both physically and mentally. You may experience higher levels of frustration or depression, and this can negatively affect your energy levels. [57>

One recent study showed that a sedentary lifestyle is one of the leading causes of adults not exercising as they should. [58> Another study showed that women who exercised even a small amount had increased energy levels over women who didn't exercise at all. When you exercise, your body starts to pump oxygen-rich blood throughout your body, and this can help to encourage energy production. [59>

15. Poor Diet

Did you know that your diet could wreak havoc on your energy levels? Unhealthy eating habits and a generally poor diet include either undereating, overheating, eating too many unhealthy foods that have high fat or sodium content, eating a lot of sugar or not having enough fibre in your diet. A poor diet directly affects your nutrient intake, and this includes your energy levels, mineral and vitamins. [60>

Since a poor diet means that you're most likely not getting the nutrients and vitamins your body needs to perform vital functions, your body can quickly become sluggish and make you feel like you have no energy or very low energy.

One study polled 117 students on their fatigue levels and their eating habits. They found that the students who had a generally poor diet or who ate sporadically experienced lower energy levels compared to students who ate a healthy diet and who ate on a schedule. [61>

Another study followed stroke patients and measured their fatigue levels in relation to their diets after they discharged from the hospital. They found that the stroke survivors who followed the hospital's diet recommendations and got enough nutrients had overall higher energy levels than the stroke survivors who ate a poor diet. [62>

A poor diet can result in problems for your organs and your cardiovascular system, and this includes plaque buildup in your arteries and fatty formations around your liver. This makes your body work harder, and this can result in drained energy stores and the feeling of constant fatigue.

Changing your diet can help ensure that your body gets all of the nutrients and vitamins it needs to accomplish all of its functions and produce enough energy to keep you feeling awake and motivated.

Bottom Line

Everyone would like to have higher energy levels and feel more motivated to get through the daily to-do lists. These 15 things can cause a drain on your energy, and you may not even realise that it's happening! Some of these things can get worse if you don't change your habits like alcohol intake, diet, dehydration and vitamin deficiencies.

Additionally, these 15 things can cause your energy levels to fluctuate from one end of the spectrum to the other. If you adjust some of your habits, you should see your low energy levels start to rise, and this means that you'll be able to get through your tasks without feeling drained or fatigued.

As always, you should talk to your doctor before you make any drastic changes to or for your lifestyle because they can monitor you and/or warn you of any possible risks of complications that you may set yourself up for. You can try one or try a few and see which ones help raise your flagging energy levels, and slowly improve small areas of your lifestyle until you reach the high energy levels that you're after.

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