Lethargy : Causes, Symptoms, Diagnosis & Treatment


Lethargy is a state of tiredness, listlessness, lack of energy or fatigue. Lethargy is mostly accompanied by depression, decreased motivation, and apathy. All of us has experienced being lethargy multiple times in our life after going through emotional and physical stress. Lethargy can also be caused by medications or underlying systemic diseases such as anaemia, diabetes, chronic obstructive pulmonary disease, etc. Lethargy due to emotional or physical stress resolves itself as soon as you modify your lifestyle while the diseases causing lethargy should be treated. 

In some cases, lethargy can last for days or even weeks after you perform the activities causing emotional and physical stress.


Causes of lethargy

 Lifestyle factors are the most common causes. These factors include:

  • Eating disorders 
  • Consumption of alcohol and drug abuse 
  • Excessive physical activity 
  • Deprivation of sleep
  • Lack of physical exercise
  • Use of drugs such as antihistamines and cough syrups 

Medical conditions of causing tiredness are:-

  • Anxiety 
  • Anaemia
  • Acute hepatic failure 
  • Cancer, chronic obstructive pulmonary disease 
  • Chronic fatigue syndrome
  • Cardiovascular diseases such as cardiac stroke and cardiomyopathy
  • Neurological disease like fibromyalgia, meningitis, Parkinson’s disease
  • Sleep apnea 
  • Endocrine abnormalities like hypothyroidism, hyperthyroidism, pituitary cancer, etc.
  • Fever, dehydration 

Some medical conditions like major depression, postpartum depression, and postmenopausal syndrome are associated with the lethargy.

Signs and symptoms associated with lethargy


These signs and symptoms are the underlying pathologies causing lethargy. These signs and symptoms differ according to the disease they are suffering from. Some of the common signs and symptoms in people with lethargy are mentioned below

Symptoms of lethargy

  1.  Shortness of breath 
  2. Palpitations
  3. A headache 
  4. Blurring of vision
  5. Dizziness
  6. Chest pain 
  7. Intermittent claudication 


  1. Pallor of mucous membrane 
  2. Tachycardia 
  3. Bounding pulse
  4. Tachypnea 
  5. Cold, clammy skin
  6. Systemic flow murmur at the apex 

Diagnosis of lethargy

Lethargy is nonspecific symptoms of many underlying diseases of the body. It does not always require clinical diagnosis and treatment. It is always recommended to consult your doctor if the lethargy does not go away in a day.

In most cases, the diagnosis of lethargy is made by history taking and clinical examination of the patient. Sometimes it needs to be worked up with investigations such as blood tests, chest x-ray, ultrasonography of the whole abdomen, urine analysis, etc. If a neurological cause of the lethargy is suspected then a CT Scan of the brain or MRI of the brain will be needed.

Treatment of lethargy

       Lethargy is commonly caused by physical and emotional stress. These cases do not require medical treatment and are resolved with adequate sleep, intake of plenty of water, meditation, healthy dietary habits, light physical exercises, etc. 

However, in some cases of Lethargy medical treatment is essential and sometimes life-saving.


Lethargy with following symptoms needs medical attention

  1. Suicidal thoughts or thoughts of harming yourself.
  2. Concerns about harming people around you
  3. Chest pain 
  4. Shortness of breath
  5. Abdominal pain, pelvic pain 
  6. Feeling of passing out 
  7. A severe headache 
  8. Rectal bleeding, vomiting of blood
  9. Confusion, blurred vision 
  10. Features of shock, such as low blood pressure, tachycardia (increased heart rate), cold clammy skin, decreased urinary output etc.
  11. Altered level of consciousness 

Treatment of the lethargy is a treatment of the underlying cause of tiredness. For example 

Treatment of lethargy caused by dehydration can be improved by intravenous fluid, antibiotics, etc. In patients with hypothyroidism consumption of levothyroxine is must to prevent lethargy.

Patients with the hypothyroidism can be treated with antithyroid drugs, radioactive iodine or surgery.

Patient with features of shock needs emergency attention and needs, maintenance of airway, breathing and circulation, which can be achieved by endotracheal intubation, administration of intravenous fluid, blood transfusion (shock caused by haemorrhage) etc. People with lethargy associated with suicidal thoughts or thoughts of harming himself or people living in surrounding can be treated with antidepressants, antipsychotics, anxiolytics and behavioral counseling.

So, we should always keep in mind the danger signs associated with lethargy. This may help us and our families in diagnosing and getting medical treatment before it’s too late.


Prevention of lethargy 

  1. Late night works and insomnia are one of the major causes of lethargy. Sleeping adequately, that is sleeping for 6 to 7 hours in a day helps in preventing lethargy. Sleep cycle should be maintained on a regular basis.
  2. Consumption of plenty of water, maintaining dietary chart with healthy foods and containing a large number of vegetables and fruits helps.
  3. Regular physical exercise not only helps in reducing the body weight but also helps in relieving stress and making you mentally and physically active.
  4. Mediation and yoga help in relieving stress. It also helps in maintaining your mind and body active.
  5. Jobs taking a toll on your body if possible should be changed. When changing jobs is not possible you can take breaks and go on vacation. Changing jobs or going on break may help you in relieving the stress and also gets you a time of your own to relax.
  6. Consumption of multivitamins can also help in preventing lethargy. It is recommended to consume multivitamins only after consulting your healthcare provider.
  7. Treatment of underlying pathological conditions and regular follow up.

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