Health Awareness blog

• Diabetes mellitus – Patients usually present with polyuria (urinate a lot), polydipsia (drink a lot) and polyphagia (eat a lot). The patients usually has a concurrent weight loss.
• Hypothyroidism – fatigue is a prominent features apart of other symptoms like weight gain, cold intolerance dry skin, constipation and menstrual irregularities
• Drugs – beta blockers, reserpine, diuretics (mainly due to hypokalemia), antihistamine, antidepressants, tranquilizers, steroids, narcotics, alcohol, etc
• Chronic sleep deprivation
• Congestive heart failure – fatigue in this patients indicated reduce cardiac output.
• Occult infection
• Iron deficiency anemia
• Obstructive sleep apnea – excessive daytime somnolence
• Renal failure
• Chronic fatigue syndrome – the fatigue lasting longer than 6 months duration. The affected person usually has less than 50% reduction of their physical capacity.
• Cushing syndrome
• Occult cancer – common cancers associated with fatigue are leukemia, lymphoma and pancreatic cancer. The patients usually also have adenopathy, lymphadenopathy and night sweats.
• Addison disease
• Myasthenia gravis – early stage of illness involves the cranial muscles lead to ptosis, diplopia and chewing fatigue. Muscle weakness exacerbated by repeated use.
• Infectious mononucleosis – acute onset of prominent fatigue
• Depression – patients usually have symptoms of fatigue, sleep disturbance, anorexia and anhedonia (loss interest of any activity)
• Panic disorder
• Somatization disorder

Reference:

1. Murray Longmore et al. Oxford Handbook of Clinical Medicine. 7^th edition.
2. David S. Smith et al. Field Guide to Bedside diagnosis. 2^nd edition. 2007. Lippincott Williams and Wilkins.
3. Tao Le et al. First Aid for the Family Medicine Boards. McGraw Hill. 2008.

Fatigue or lethargy is a very vague symptom. The feeling is extremely common and varies in normality. Only 1 in 400 episodes of fatigue will lead to the doctor consultation. Anyone can present to the clinic with this symptom and leave the doctor wondering why they are fatigue. Is that necessary? Well, if we have some ideas about cause of fatigue, maybe we have some ideas about the fundamental behind it.

Fatigue can be divided by organic fatigue and psychological fatigue. We need to rule out any organic fatigue before we can safely say that it is a psychological fatigue. Prompt diagnosis is important because the management varies largely.

Organic fatigue is characterized by true physical weakness. The exhaustion is aggravated by physical activity and improves to some extend after the patient take some rest. The history usually less than 2 months and there is unintentional weight loss about 10%. Most organic problems of lethargy have a tell tale that might give some ideas what the cause might be. Make sure you tell the doctor all the associated signs and symptoms.

Psychological fatigue is more towards lack of primary inertia to initiate a task or particular physical activity. However, if this task been proceeds, it can be performed. This type of fatigue does not exacerbate by exertion and most of the time does not improve by resting. The patients might describe it as “I feel tired all the time. I may take some rest, but it usually not helping.” Some patients can come out with multiple and non specific symptoms. Any life stressful events, anxious or depressed symptoms and appearance can give some clues.

In patients with history of fatigue for more than 1 month, about 60-70% has medical or psychiatric illness. Among psychiatric diagnosis, depression, panic disorder and somatization disorder are the most common.

A diagnostic approach involves careful history taking together with proper physical examination.  In some selected cases, some investigations like FBC (full blood count) and ESR (erythrocyte sedimentation rate), urea and electrolytes, plasma glucose, thyroid function test (TFT) and chest X-ray can be considered. Follow up patients to see how the progress and any emotional development.

Differential diagnosis of fatigue is very wide and management will be depends on the right diagnosis. Identification of unusual organic cause takes one a great skill to detect. Even though it is clear that the patient is depressed, chronic causes need to be ruled out. Whatever the cause, avoid the early closure. Do not imply to the patients that “it is all in your head”. Give the patients time to talk. Most of the time, the right diagnosis is lies behind a good history taking.

Reference:

1. Murray Longmore et al. Oxford Handbook of Clinical Medicine. 7^th edition.
2. David S. Smith et al. Field Guide to Bedside diagnosis. 2^nd edition. 2007. Lippincott Williams and Wilkins.