Tired and Fatigued all the time – Know the causes!!

Being tired and weak all the time may be a symptom of an underlying serious disease.

Fatigue is a subjective feeling of tiredness and lack of energy during or after physical activity or avoiding/ lack of interest in physical activity.

Individuals must be evaluated for medical causes of tiredness and fatigue prior to associating it with psychosocial factors.

Fatigue and being tired is a very general term … 


It is very difficult to define fatigue since it’s a very general term. Dyspnea or shortness of breath, somnolence or excessive sleeping and muscular weakness are specific terms which need to be differentiated as these terms may be used simultaneously by the patient.

chronic fatigue syndrome
Chronic fatigue syndrome

Furthermore, an individual may have fatigue or lethargy in combination with shortness of breath, weakness and other symptoms. Chronic fatigue or chronic fatigue syndrome is another entity in which the symptoms last more than 6 months.

Tiredness or fatigue is a very common symptom, almost everybody has experience at some point in his life.

The most common causes of feeling tired all the time include:

inadequate sleep and tired
inadequate sleep
  1. Inadequate sleep
  2. Increase working hours
  3. Stress, relationship difficulties, illness in the family,
  4. Lack of exercise
  5. Chronic medical conditions

Other than the causes listed above chronic idiopathic fatigue syndrome is also one of the major causes of tiredness and fatigue.

What are the medical causes of feeling tired and fatigued?

The following list of medical conditions may lead to lethargy, fatigue or tiredness.

pallor of hands in an anemic patient
  1. Hematologic causes – Anemia and leukemias
  2. Endocrine causes –  Hypothyroidism, Addison disease, Cushing syndrome, hypopituitarism, diabetes mellitus, and hypogonadism.
  3. Electrolyte disturbance – Hypokalemia, hypercalcemia and hyponatremia
  4. Infectious causes – Hepatitis, endocarditis, tuberculosis, mononucleosis, parasitic infections and, HIV infection.
  5. Malignant causes – All malignant tumors
  6. Cardiovascular causes – Heart failure and Hypotension
  7. Pulmonary causes – Chronic obstructive pulmonary disease and other chronic lung diseases
  8. Metabolic causes – Chronic renal failure, chronic hepatic failure
  9. Medications – Sedatives, opiates, antidepressants, and antihypertensive drugs.
  10. Miscellaneous – Insomnia, Sleep apnea syndrome, gastroesophageal reflux, allergic rhinitis, Myopathy, Dementia and delirium

A brief discussion of the important causes of fatigue and tiredness:

  1. Anemia
  2. Thyroid disorders
  3. Cushing’s and Addison’s disease
  4. Diabetes
  5. Hypokalemia
  6. Chronic infections (Tuberculosis and HIV)
  7. Malignancies
  8. Chronic renal failure
  9. Chronic liver disease
  10. Heart failure
  11. Hypogonadism

Anemia is a major cause of tiredness:

causes of tiredness
anemic baby

Patients with anemia may notice progressive Pallor, easy fatigability, tiredness, palpitations, headaches, and shortness of breath.

Anemia in adult females is usually due to iron deficiency because of excessive menstrual blood losses. Iron deficiency anemia in males is usually due to the anemia of blood loss from the gastrointestinal tract.

causes of tiredness
pale conjunctiva in an anemic patient

Other than anemia of iron deficiency patients can have folate deficiency and vitamin B12 deficiency as well. These patients usually are having a chronic diarrheal state like celiac disease, malnutrition or are strict vegetarians.

Anemia apart from the deficiency of enzymes and Minerals can also be secondary to early destruction of red cells, as in hemolytic anemias like thalassemia.

anemic and tired
a thalassemic patient

Patients with chronic conditions like malignancies, liver and renal diseases can also have anemia which is usually due to anemia of chronic disease.

In a group of patients, anemia can also be due to inadequate production by the bone marrow as in aplastic anemia.

Anemia can be diagnosed via simply doing a simple blood test called as blood CP and you can find reduced hemoglobin and hematocrit.

The WHO cut-offs for a normal hemoglobin in males and females are 13.5 g/l and 12.5 g/l respectively.

Anemia is not a diagnosis!!

Anemia is not a diagnosis and further tests like serum ferritin, Vitamin B12 and folate levels and investigations for the underlying deficiency states should be carried out.

These tests may include:

Treatment of anemia depends upon the cause and the deficiency States. Simple replacement of the hematinics can be sufficient in patients who are malnourished or vegetarians.

vitamins deficiency causes tired

Autoimmune Hemolytic anemias require treatment with steroids and immune-modulators. Splenectomy may be considered for hereditary spherocytosis and autoimmune hemolytic anemias.

malaria anemia  tired
malaria transmission via blood

Blood transfusions and iron chelators to avoid iron overload may be the only treatment options for congenital hemolytic anemias like thalassemia and aplastic anemia. Bonemarrow transplantation may benefit a subset of patients with these disorders.

Feeling tired all the time – know your thyroid status:

tired and thyroid disorders
The thyroid gland

Thyroid disorders can also cause excessive tiredness. Both hyperthyroid and Hypothyroid States can lead to excessive tiredness and fatigue.

Hypothyroid patients have excessive sleep, cold intolerance, constipation, weight gain, and proximal muscle weakness while patients with hyperthyroidism can have heat intolerance, insomnia, and proximal muscle weakness.

tired and thyroid
Thyroid ophthalmopathy and progressive dermopathy resembling elephantiasis

Diagnosis is confirmed by doing thyroid function tests (TSH, T3, and T4)

Treatment depends upon the condition. Thyroxine replacement in hypothyroidism or antithyroid drugs + – thyroid surgery or radioiodine therapy in hyperthyroid States

Feeling tired all the time – Check your cortisol levels

Cortisol excess also called Cushing syndrome can also lead to proximal muscle weakness and easy fatigability, Diabetes, hypertension, bone fragility, and osteoporosis.

weight and cushings
weight gain, striae and buffalo hump in Cushing’s syndrome

Similarly, cortisol deficiency called adrenal insufficiency or hypo-aldosteronism can also cause fatigue, abdominal pain, nausea, vomiting, and weight loss.

Diagnosis is confirmed by doing an early morning serum cortisol levels, 24-hour urine for cortisol levels, an overnight dexamethasone suppression test, and a short synacthen test for adrenal insufficiency. Treatment depends upon the cause.

Feeling tired and numb – Check your Blood Sugars

complications of diabetes

Diabetes is one of the major causes of tiredness and fatigue. In diabetic individuals, the blood sugars in the plasma are elevated but the cells, tissues, and organs are starving.

Diabetes leads to serious complications …
complications of dibetes
diabetic foot ulcer

Diabetes also leads to cellular dehydration, nerve dysfunction, early atherosclerotic disease, and chronic renal failure. All these, in turn, can add on to the symptoms of fatigue and lethargy. Diagnosis of Diabetes is discussed in detail.

Diabetes leads to serious complications. These complications include both microvascular and macrovascular complications. Complications of diabetes are discussed in detail. Treatment of diabetes requires an individualized approach.

Feeling tired all the time – Check your electrolytes

Renal tubular acidosis
Knocked knees in a patient with RTA

Symptoms of hypokalemia can range from muscle cramps, fatigue, lassitude to weakness and muscle paralysis. Hypokalemia can occur in patients due to excessive gut losses, renal losses or malnutrition.

Diarrhea is a common cause of hypokalemia due to gi cause. Causes of hypokalemia due to renal wasting include diuretic use and renal tubular acidosis. Treatment aims at potassium replacement via oral tablets, syrups or in severe cases iv.

Chronic infections cause tiredness too!

causes of tiredness
bilateral upper lobes involvement in TB

Chronic infections like tuberculosis, fungal infections, and HIV infections can lead to asthenia, weight loss, anemia (of chronic disease) and central nervous system manifestations.

Certain drugs used to treat these conditions can also have adverse neurological effects and sedative properties leading to lethargy and tiredness.

Cancers – Important cause of fatigue and getting tired easily

causes of tiredness
cancer and fatigue

Cancer cachexia is the medical term used when patients with a malignant condition develop marked weight loss. The diagnosis of malignancy or cancer itself is horrible news for the patient and leads to anxiety and depression.

cancer cachexia
cancer cachexia

Furthermore, cancers are associated with anorexia, nausea, vomiting, skeletal pains, anemia, and weight loss. In addition, chemotherapeutic drugs have serious adverse effects ranging from bone marrow suppression, oral ulcers, diarrhea (mucositis), electrolyte disturbances like hyponatremia and make the patient prone to opportunistic infections.

Chronic renal failure – an important cause of tiredness

causes of tiredness
kidney disease patient on hemodialysis

Chronic renal failure has subtle symptoms these include symptoms of anemia (like pallor, palpitation, lethargy, and headache), metabolic bone disease (defective vitamin D activation leads to hypocalcemia and hypophosphatemia, proximal muscle weakness and muscle pains), and symptoms of acidosis and uremia.

Chronic liver disease may present as fatigue and tiredness

Jaundice in a patient with liver disease

The liver is a major organ involved in metabolism and detoxification of various waste products. Patients with liver disease develop chronic fatigue, anorexia, and muscle wasting.

Since albumin, proteins and gamma globulins are one of the major synthetic functions of the liver, patients with liver disease may develop hypoalbuminemia and hypoproteinemia. Thus patients develop muscle wasting.

hepatic encephalopathy
hepatic encephalopathy

Similarly, the elevation of ammonia levels in the blood may lead to an altered sleep pattern, drowsiness, lethargy, and unconscious state. Patients develop anemia as a result of gastrointestinal bleeding and anorexia, further aggravating the problem.

Another cause of anorexia, nausea, and vomiting in these patients is the mechanical effect of ascites on the stomach, stomach ulcer, and varices.

Heart failure – cardiac cachexia

causes of tiredness
congestive heart failure

Heart failure is another major cause of fatigue and muscle wasting. Cardiac cachexia is the term used to describe muscle wasting and weight loss in patients with heart failure. These patients have chronic liver congestion that leads to anorexia and decreased protein synthesis.

cachexia tired
cardiac cachexia

Patients may also feel tired and lethargic because of the chronically reduced blood and oxygen supply to major organs of the body like the brain, kidneys, liver, and muscles.

Drugs used to treat these conditions may potentiate the problem. These include beta blockers, nitrates, and diuretics.

Hypogonadism – a common cause of fatigue and getting tired easily.

causes of tiredness
Androgens are required for muscle strength

Apart from the functions related to sexuality, Androgens are required for muscle strength and prevention of osteoporosis. Hypogonadism is often missed in the adults and elderly because of the subtle symptoms.

Common features of hypogonadism include loss of libido, lack of energy and strength, tiredness, early osteoporosis, weight gain, and dyslipidemias. In contrast to elderly individuals, prepubertal individuals have a poor development of secondary sexual characteristics.

Morning serum levels of testosterone confirm the diagnosis in most cases. Replacement of androgens in the form of patches, tablets or injections is the treatment.

Read More …

  1. Pituitary Gland – The master hormone-producing gland
  2. Jaundice is not a disease, its a symptom
  3. How to interpret liver function tests
  4. Blood CP – the most common blood test ordered by physicians
  5. Never ignore a chronic cough



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