Fatigue Symptoms, Causes, and Treatment


Fatigue is mainly a symptom and not a disease in itself

Fatigue is a term like a feeling of tiredness or lack of energy. Hence it isn’t the same as simply feeling drowsy or sleepy. When you’re fatigued, you have no motivation and no energy. Being sleepy may be a symptom of fatigue, but it’s not the same thing.


Fatigue definition and facts

  • Laziness or fatigue (either physical, mental, or both) is a symptom that may be difficult for the patient to describe, and words like sluggish, exhausted, and tired may be used.
  • Taking a careful and complete history is the key to help to make the underlying diagnosis of the cause for the symptom of fatigue. However, in about a third of patients, the cause is not clear and the diagnosis is unclear.
  • There are numerous causes of fatigue symptoms. Examples of some treatable causes of fatigue include anemia, diabetes, thyroid diseaseheart diseaseCOPD, and sleep disorders.
  • Long-lasting complaints of fatigue do not equate to chronic fatigue syndrome. Specific guidelines as set by the CDC need to be met to make that particular diagnosis.

What is fatigue? What does it feel like?

Fatigue can be described as a lack of energy and motivation (both physical and mental). This is different from drowsiness, a term that describes the need to sleep. Often a person complains of feeling tired and it is up to the health care professional to distinguish between fatigue and drowsiness, though both can occur at the same time. Apart from drowsiness, other symptoms can confuse us with fatigue. Such as including shortness of breath with activity and muscle weakness. Again, all these symptoms can occur at the same time. Also, fatigue can be a normal response to physical and mental activity. Generally, in most normal individuals it is quickly relieved by reducing the activity.

Fatigue is a physical, psychological or combination complaint

Especially fatigue is a very common complaint and it is important to remember that it is a symptom and not a disease. In this case, many illnesses can result in the complaint of fatigue and they can be physical, psychological, or a combination of the two.

Often, the symptom of fatigue has a gradual onset and the person may not be aware of how much energy they have lost until they try to compare their ability to complete tasks from one-time frame to another. They may presume that their fatigue is due to aging and ignore the symptom. Thus this may lead to a delay in seeking care.

While it is true that depression and other psychiatric issues may be the reason for fatigue, it is reasonable to make certain that there is not an underlying physical illness that is the root cause.

Accordingly, Individuals with tiredness may have three primary complaints; however, it can vary in each person.

Three primary complaints of laziness

Such as there may be a lack of motivation or the ability to begin an activity. The person tires easily once the activity has begun. Also, the person has mental fatigue or difficulty with concentration and memory to start or complete an activity. While fatigue can last for a prolonged period of time, the presence of chronic fatigue is different than chronic fatigue syndrome, which has a specific set of two criteria set for by the Centers for Disease Control and Prevention as follows:

Have severe chronic fatigue for at least six months or longer with other known medical conditions.

Concurrently have four or more of the following symptoms:

  • post-exertional malaise
  • impaired memory or concentration
  • together with unrefreshing sleep
  • also muscle pain
  • multi-joint pain without redness or swelling
  • In addition to tender cervical or axillary lymph nodes
  • together with a sore throat
  • headache

Other words that a person might use to describe fatigue may include:

  • lethargic
  • listless
  • lack of energy
  • tired
  • worn out
  • weary
  • for the most part, feeling exhausted
  • malaise
  • also feeling run down.

What are the causes?

There are numerous potential causes of fatigue as a major complaint. They range from those that cause the poor blood supply to the body’s tissues to illnesses that affect metabolism, from infections and inflammatory diseases to those that cause sleep disturbances. Also, it is a common side effect of many medications. While numerous patients with psychological conditions often complain of laziness (physical and mental), there are also a group of patients where the cause of laziness is never diagnosed.

The following lists summarize some common causes of fatigue but are not meant to be comprehensive:

  • Metabolic/ Endocrine: anemia; hypothyroidismdiabetes; electrolyte abnormalities; kidney diseaseliver disease; Cushing’s disease
  • Cardiac (heart) and Pulmonary (lungs): congestive heart failure; coronary artery disease; valvular heart disease; COPDasthma; arrhythmias; pneumonia
  • Vitamin Deficiencies: vitamin B12 deficiency, vitamin D deficiency, folic acid deficiency, iron deficiency.
  • Psychiatric (Mental Health)depression; anxiety; drug abuse; alcohol abuse; Eating disorders 
  • Infectious disease: infectious Mononucleosis; hepatitis; tuberculosis; cytomegalovirus; HIV infection; influenza (flu); malaria and many other diseases
  • Medications: antidepressants; anti-anxiety  medications; sedative medications; medication and drug withdrawal; antihistamines; steroids; some blood pressure medications; some antidepressants
  • Sleep Problems: sleep apnea; reflux esophagitis; insomnia; narcolepsy; shift work or work shift changes; pregnancy; Extra night hours at “work”
  • Othercancer; rheumatology illnesses such as rheumatoid arthritis and systemic lupus; fibromyalgia; chronic fatigue syndrome; normal muscle exertion; obesity; chemotherapy and radiation therapy.

What are the signs and symptoms?

Above all fatigue is a symptom of an underlying disease and is described in many ways from feeling weak to being constantly tired or lacking energy.

Such as there may be other symptoms links depending upon the underlying cause.

  • Individuals with heart disease, lung disease, or anemia may complain of associated shortness of breath or tiring easily with minimal activity.
  • Persons with diabetes may complain of polyuria (excess urination), polydypsia (excess thirst), or change of vision.
  • Those who have hypothyroidism may also have symptoms of feeling cold, dry skin, and brittle hair.

It is important that the health care professional consider the complaint of laziness in the context of the whole patient to try to come to an accurate causative diagnosis.

What is the test to diagnose fatigue?

For the most part, the key to finding the cause of tiredness or laziness in a patient is the care the health care professional takes in compiling a medical history. It is important to ask questions not only about the loss of energy but also about other potential problems that the patient may be experiencing such as shortness of breath, sleep patterns, hair loss, the colour of the stools, or any of the myriad of questions that might provide information as to what organ system may be involved.

Generally, a history is taken by the health care professional asking questions about the quality and quantity of fatigue. Furthermore examples of some of the questions the health care professional may ask.

Examples of some of the questions include:

  1. Does the patient feel well in the morning when they wake?
  2. Do the fatigue progress through the day?
  3. person nap unexpectedly or take excessive amounts of stimulants such as caffeine to complete daily activities?
  4. the fatigue come on gradually or abruptly?
  5. Is it a daily occurrence or intermittent/periodic?
  6. For example what makes it better and what makes it worse?
  7. How has the patient’s life changed because of the fatigue?
  8. Is the fatigue more mental than physical?

Other associated symptoms with fatigue include:

  • weight loss,
  • chest pain and shortness of breath,
  • vomiting and diarrhea,
  • fevers and chills,
  • muscle weakness or pain
  • anxiety and depression.


It is also appropriate for the health care professional to ask questions about the patient’s social situation and to also ask about their psychological state of mind. Also, alcohol and drug abuse screening questions should be expected as routine.

Because fatigue is such a non-specific symptom, each answer may direct the health care professional to explore a different potential cause.

Physical examination

For the most part, a full physical examination is important to look for underlying signs of illness. Also, the general appearance of the patient is important looking for hygiene, vital signs, and evidence of anxiety or agitation. Such as examination and evaluation of the different systems of the body ( heart, lungs, abdomen, neurological system, etc.) and combining any abnormal findings with the clues found in the history taking may help make the diagnosis.

Also, special attention may be taken to palpate (feel) for an abnormal thyroid gland, swollen lymph nodes, listen for abnormal heart sounds including murmurs, and to check for normal muscle tone and reflexes.

Therefore depending on the findings in the history and physical examination, blood tests and other imaging studies may be ordered. Also, initial screening blood tests may include:

  • CBC (complete blood count that includes a red blood cell, white blood cell, and platelet count);
  • electrolytes (sodium-potassium, chloride, carbon dioxide, and sometimes calcium and magnesium)
  • glucose (blood sugar);
  • BUN/ creatinine (to measure kidney function)
  • TSH or thyroid-stimulating hormone;
  • monospot
  • ferritin
  • tests for deficiencies in vitamins B12, D folic acid, and iron
  • CPK (elevated in illnesses that cause muscle inflammation) and/or
  • ESR or erythrocyte sedimentation rate (nonspecific blood marker for inflammation in the body).

CPK and ESR screening tests are rarely done initially. Such as the decision to obtain X-rays, CT, scans, electrocardiogram (ECG, EKG), and other imaging or testing will depend upon the individual patient’s circumstances and what the health care practitioner suspects may be the underlying cause of the fatigue.

What is the treatment for fatigue?

Since fatigue is a symptom of an underlying condition, the treatment depends upon the condition that is causing the fatigue, regardless of whether it is physical, psychological or a combination of the two.

There may be a lag time between when the illness has been treated and the intensity of fatigue symptoms; some symptoms may resolve as soon as the underlying condition is treated. For example, individuals who are anemic feel much better as soon as their red blood cell count increases, while those recovering from infectious mononucleosis may require weeks to have their energy levels return to normal.

Can fatigue be prevented?

In brief, Fatigue, as a symptom can occur as the result of many causes, and therefore, prevention is not an issue. More importantly, the early recognition of fatigue will allow a person to seek medical care and potentially have an earlier diagnosis of the underlying cause made.

In short sometimes, symptoms like fatigue arise gradually and it is difficult for the person to realize that there is a problem. For the most part self-awareness of gradual decline in body, performance is often difficult as a person makes repeated small accommodations to complete daily activities. As well as asking your family and friends for support, you may find it useful to talk to other people with chronic fatigue.