A comprehensive list of potential reasons for why you feel so fatigued  

Do you often ask yourself, “Why am I always tired?”  

While it’s normal to feel tired from time to time from missing a night’s sleep or two, it isn’t normal to constantly feel exhausted.   

 Many people put up with fatigue and don’t realise it could have an underlying cause such as a medical condition, lifestyle choices, or the environment.   

That’s why it’s important to talk with a health professional if you never feel well-rested and have low energy. If you’re experiencing any of the following symptoms, you could be suffering from chronic fatigue.¹ 

• Physical: overtired, sore muscles, headaches, dizziness  

• Mental: memory issues, poor concentration, slow reflexes  

• Emotional: moodiness, irritability, feeling down or depressed  

Your doctor might ask you about your family medical history, examine you physically and carry out various tests, such as blood work, to better understand why you are feeling constantly tired. You may also be asked some of the following questions so your healthcare professional can make a more accurate diagnosis: 

• Have you been feeling drowsy or is it more a feeling of weakness?   

• Did your fatigue come on suddenly or did it develop over time?  

• Are there different times of the day when you feel more tired?   

• How has your mood been over the past month?  

• Has something happened recently that might have triggered your fatigue?   

• What is your diet like, and do you get regular exercise?

Causes of fatigue  
 

Lack of sleep   
Unsurprisingly, poor sleep is one of the main culprits when it comes to chronic fatigue.   
  
If poor sleep is suspected as the cause, your doctor may take a “sleep history” to ascertain whether poor sleeping habits or even a sleep disorder, such as obstructive sleep apnea, could be responsible. Your doctor might ask:

• Do you snore?  

• On average how much sleep do you get each night?  

• Do you have trouble getting to sleep?  

• Do you wake up during the night?  

• Do you wake up gasping for air?   

Obstructive sleep apnea 
Obstructive Sleep Apnea (OSA) is a chronic condition where your breathing repeatedly stops and starts while you sleep, which deprives you of the restorative rest you need to function properly.² 

This disrupted sleep pattern is a common cause of fatigue as well as other issues including headaches, memory problems, poor concentration, and irritability.^2,3  

If you’re diagnosed with OSA, your doctor may recommend lifestyle changes or look at different treatment options, such as CPAP therapy.   

Depression 
If you have depression, you may also experience fatigue.⁴ 

Being depressed can affect your sleep patterns and energy levels. You may have trouble falling asleep, staying asleep and might wake up repeatedly throughout the night. Some people with depression sleep too much while others do not sleep enough – all of this can lead to the feeling of being tired all the time.⁴  

When left untreated, depression can cause ongoing issues with fatigue which is why it is important to speak with your doctor about ways to treat it. If you are already on medication, they may consider switching your antidepressant to something else.⁴  

Anemia 
Anemia is when you do not have enough red blood cells or hemoglobin, a substance which helps carry oxygen around the body. Therefore, when you have anemia you can be deprived of oxygen and because of this you can constantly feel overtired.⁵  

Hypothyroidism 
When your thyroid gland fails to produce enough thyroid hormone this is called hypothyroidism, which is a common disease, especially in women. With reduced levels of thyroid hormones, you can often feel tired because these are what control your metabolism.⁶   

To determine whether your thyroid is functioning properly, your doctor will get you to take a blood test. If it is discovered you have hypothyroidism, they will usually prescribe medication to treat your underactive thyroid.  

Heart disease 
If you’re feeling tired all the time and find you don’t even have enough energy to exercise, this can sometimes point towards heart disease.   

With heart disease, the heart may not be pumping blood around your circulatory system as well as it should which deprives your body of the oxygen it needs to function properly.⁷  

So, if you’re experiencing fatigue and have noticed everyday activities have become a struggle, you should consider talking with your doctor as soon as possible.   

Hepatitis 
Simply put, hepatitis is when your liver is inflamed. It’s considered to be acute if the inflammation lasts six months or less but becomes a chronic condition when it persists beyond six months. Hepatitis is typically the result of a virus or alcohol damage from prolonged use.^8,9,10 

The liver is responsible for many important processes in the body. It’s the main filtration system, cleaning blood and turning toxins into waste. When it’s inflamed it can no longer perform these functions properly and consequently you might feel fatigue.   

Your doctor can organize a liver test to determine if this is the cause of your tiredness.  

Diabetes 
Insulin is a hormone that helps your body convert blood sugar or blood glucose into energy. When you have diabetes your body either doesn't make enough insulin or it doesn't use it as effectively as it should. The resulting imbalance may cause you to experience fatigue.¹¹  

Medications 
Many different medications can cause fatigue. Your doctor may look at your patient history and any current treatments to determine whether you need to stop or change a particular medication.   

Stress 
Stress is a normal and necessary response to a perceived threat – your body gets flooded with cortisol and other stress hormones like adrenaline that get you ready to act. However, when you’re constantly exposed to stressors you stay in this elevated state which puts you at increased risk of many health problems, including fatigue.¹²  

Diet 
If you’re not eating a healthy, balanced diet you run the risk of slowing down physically and mentally. Health problems, including fatigue, can result from a diet poor in the necessary amount of essential nutrients.¹³