Fatigue: What Could Be Causing It?

by | October 6, 2020 | Articles, Optimal Health

In a world where we are always on the go, it’s no wonder many people suffer from fatigue. Between handling the demands of work, school, family, and other social relationships, it’s hard to catch a period of rest and relaxation. And, while busyness can certainly be what causes your fatigue, it could also be the result of an underlying mental or physical condition.

What is Fatigue? 

Fatigue is a persistent tiredness that limits one to do his or her usual activities. It may impact how you get by in everyday life and may be reflecting a dysfunction in your body. For some, it’s temporary, while in others, it is chronic and the result of a medical condition. Regardless, it’s important to get to the root cause of the issue as overlooking it could have serious, even fatal results.

Causes of Fatigue

Generally, there is a reason for fatigue, and once discovered, it can be treated by medication, supplementation and lifestyle changes. Some common causes of fatigue include: 


  • This condition is the result of not having enough healthy blood cells to carry sufficient supplies of oxygen throughout the body. 
  • Individuals with anemia may feel both tired and weak.
  • Could be long-term or temporary and mild to severe.
  • Iron deficiency may lead to the body being unable to produce enough hemoglobin, which allows red blood cells to carry oxygen to tissues. This can cause weakness and fatigue. 
  • Iron deficiency anemia is common in women of reproductive age, especially if they have heavy periods.
  • Our diet also affects our iron stores. Some of the richest sources of iron include breakfast cereals which are fortified with iron (watch for the sugar content, however!), oysters, white beans, dark chocolate, beef liver, lentils, spinach and tofu.
  • A more serious cause of iron deficiency anemia is internal bleeding (e.g., bleeding from the gastrointestinal tract can cause a reduction in hemoglobin and therefore oxygen-carrying capacity). 
  • Whenever anemia is diagnosed, through a blood test, it is important to determine what the anemia is due to (e.g., iron deficiency, vitamin B12 deficiency, anemia of chronic disease, etc), do the appropriate workup, and then treat anemia accordingly.


  • This is a condition where an underactive thyroid gland doesn’t make enough thyroid hormone to keep the body running normally.
  • Body processes slow down, which can result in fatigue, weight gain or trouble losing weight, being constipated, feeling cold, depressed, forgetful, and more.

Vitamin B12 Deficiency

  • Vitamin B12 helps make DNA, red blood cells and nerves in the human body. It comes from animal-based foods like dairy products, eggs, meat, and fish. Those who follow a vegan or vegetarian diet, and those who have trouble absorbing B12 can take vitamin B12 as a supplement (orally, intranasally or as an injection). 
  • A deficiency in vitamin B12 can cause weakness, fatigue, anemia, numbness and tingling, difficulty walking, a swollen, inflamed tongue and other signs and symptoms.
  • It may be caused by a vegetarian lifestyle, medication, pernicious anemia, Crohn’s Disease, or immune system disorders.
  • Some of the conditions which can compromise vitamin B12 absorption include medical conditions such as Celiac disease, pernicious anemia and Crohn’s disease, as well as a history of bariatric weight loss surgery. The use of medications for heartburn can also lead to vitamin B12 deficiency due to a reduction of acid production in the stomach, which is needed for vitamin B12 absorption. The use of metformin, a diabetes medication, can also increase the risk of vitamin B12 deficiency. Individuals consuming a strictly vegetarian or a vegan diet are also at risk of vitamin B12 deficiency if they are not consuming supplemental B12.

Vitamin D Deficiency

  • This vitamin is needed to support bone health and has also been found to play an important role in blood glucose regulation, blood pressure regulation, immune system function and mood, although more studies are needed to better understand these correlations.
  • A deficiency can lead to bone pain, increased risk of fracture, weakness and fatigue.  A deficiency has also been found in some studies to contribute to the risk of cancers, cardiovascular disease, upper respiratory infections and viruses responsible for the flu and Covid-19.
  • Vitamin D deficiency can be caused by not consuming enough Vitamin D (fatty fish, such as salmon and tuna, are some of the richest sources), having limited sunlight exposure, having more melanin or darker skin, obesity, digestive problems, or failing kidneys.

Autoimmune Conditions

  • These conditions occur when the immune system mistakes part of the body as foreign and releases auto-antibodies to attack healthy cells.
  • Debilitating tiredness is a common symptom with autoimmune conditions like systemic lupus erythematosus, type 1 diabetes, Celiac disease, and rheumatoid arthritis.
  • Depending on the autoimmune condition in question, other symptoms may include painful and swollen joints, rashes, digestive issues, swollen lymph nodes, and other symptoms.


  • This mood disorder causes sadness, loss of interest in doing things, feeling hopeless, guilty, having low energy and memory impairment. It can affect how you behave, think, and feel.
  • It can also lead to extreme tiredness, can co-occur with anxiety, poor appetite, insomnia, and other physical symptoms.
  • If fatigue is accompanied by any of the symptoms above, it is important to get screened for depression by a healthcare provider.

Chronic Fatigue Syndrome (CFS)

  • This disorder is characterized by moderate to severe fatigue. 
  • Other symptoms include tiredness after exertion, unrefreshing sleep, problems regulating blood pressure and heart rate, trouble concentrating and/or what is commonly referred to as brain fog (cognitive impairment).
  • While chronic fatigue syndrome does not cause the immune system to be compromised, there are changes in the immune system of individuals with CFS that are observed.
  • For the diagnosis to be made, the symptoms have to be present for at least six months and occur at least 50% of the time. 
  • Infectious agents (s.a., EBV, chronic Lyme disease) are hypothesized to be implicated in some cases of CFS.


  • This condition is characterized by widespread musculoskeletal pain and tenderness in addition to fatigue and sleep disturbances. Symptoms are present for at least 3 months and are not explained by any other medical condition. 
  • Memory problems and mood symptoms commonly accompany the symptoms above.
  • Irritable bowel syndrome and headaches can be present in fibromyalgia as well.
  • There is no joint swelling or inflammation.
  • The diagnosis is made by history and a physical examination which reveals tenderness in multiple parts of the body. When there is no other illness present, laboratory results are within expected ranges. 

Lyme Disease

  • This common tick-borne illness is transmitted by the bite of a deer tick infected with Borrelia burgdorferi.
  • Symptoms include fever, chills, fatigue, body aches, headache, and a typical rash called erythema migrans.
  • If untreated, the infection can affect the heart, nervous system and joints. Arthritis is the most common manifestation of late Lyme disease.
  • If the symptoms and physical findings are consistent with Lyme disease, and there is a possibility of exposure to infected ticks, testing is done to confirm the presence of antibodies against B. burgdorferi to make the diagnosis.
  • Post-Lyme disease syndrome has been observed in 5-15% of people with Lyme disease. Symptoms may include fatigue, musculoskeletal pain, and cognitive difficulties (commonly referred to as brain fog by many patients). The cause of these symptoms and appropriate treatment is a topic of great debate in the medical literature.

Cardiopulmonary Symptoms Leading to Fatigue

  • If fatigue is the result of heart or lung disease, the following symptoms will likely be reported as well:
  • Individuals with heart disease likely also have symptoms such as shortness of breath (on exertion, or even at rest if they have severe symptoms), chest pain or pressure, heart palpitations, leg swelling, difficulty breathing when lying flat, waking up in the middle of the night gasping for air and/or cough. The specific symptoms depend on the exact condition and the severity of the condition (e.g., heart failure, arrhythmia, or angina).
  • Individuals with lung disease may have symptoms such as shortness of breath, cough and wheezing. They may have a history of smoking or exposure to other toxins that may be responsible for lung disease.
  • Individuals with sleep apnea may snore and have short periods when they stop breathing while they sleep (partners are usually the best at providing this history, as they are the ones witnessing the snoring and apneic episodes). These individuals will also typically be sleepy throughout the day and may easily fall asleep if watching TV.

Lifestyle Factors Leading to Fatigue

  • Having a poor diet and persistent nutrient deficiencies that don’t allow the body to properly fuel and function
  • Eating processed food, added sugar and ingesting toxins contributes to inflammation, which in turn, contributes to fatigue
  • Inadequate sleep (not getting seven to eight hours of sleep per night)
  • Enduring chronic stressors at home and work without the ability to appropriately channel stress
  • Sedentary lifestyle (lack of physical activity)
  • Excessive screen time
  • Neglecting exercise which can boost energy and help with sleep 
  • Consuming alcohol which is a depressant, or drugs that are stimulants and lead to insomnia
  • Not finding purpose and meaning in life
  • Lack of social relationships and a community

Red Flags

While fatigue in itself is concerning, when accompanied by night sweats, weight change, changes in appetite, shortness of breath, chest pain, jaundice, altered bowel and urinary habits, blood in stool, or other alarming symptoms, it can signify a red flag that needs to be evaluated immediately. These may indicate medical conditions like cancer, cardiopulmonary conditions, autoimmune illnesses, human immunodeficiency virus (HIV), hepatitis C, and more. If you’re experiencing these or any other concerning symptoms, immediately seek the help of a medical professional. Note, the list above provides some of the most common causes of fatigue. If you are experiencing fatigue, it is important to be evaluated by your qualified healthcare professional.

Fight Your Fatigue Today!

While feeling tired from time to time may be a normal part of life, chronic fatigue shouldn’t be. Call now to discover how Dr. Bojana and her team can not only help you find the root causes of your fatigue but can help with a plan to beat it. We look forward to working with you!

Sources include: UptoDate.com, https://ods.od.nih.gov/


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