Feeling tired or weak, even with adequate rest, can be a common symptom of various conditions, including both physical and psychological factors.

Chronic fatigue syndrome (CFS) is a complex disorder characterized by extreme fatigue that lasts for at least six months and is not improved by rest. While CFS is recognized worldwide, including in India, it can be challenging to diagnose and manage due to its unclear cause and overlapping symptoms with other conditions.

Fatigue can be associated with B12 deficiency, there are other potential causes to consider in a patient of chronic fatigue. Here are a few possible causes:

1. Sleep disorders: Certain sleep disorders, such as sleep apnea, restless leg syndrome, or insomnia, can disrupt the quality of your sleep and leave you feeling tired, even after a full night’s rest.

2. Anemia: Apart from B12 deficiency, other types of anemia, such as iron deficiency anemia, can lead to fatigue and weakness. Anemia occurs when your body doesn’t have enough healthy red blood cells to carry oxygen to your tissues effectively.

3. Thyroid problems: Hypothyroidism, a condition where the thyroid gland doesn’t produce enough thyroid hormone, can cause fatigue, weakness, and sluggishness.

4. Chronic fatigue syndrome (CFS): CFS is a complex disorder characterized by extreme fatigue that isn’t improved by rest and lasts for at least six months. Its exact cause is unknown, but it can significantly impact a person’s energy levels and overall functioning.

5. Depression and anxiety: Mental health conditions, such as depression and anxiety, can cause persistent fatigue and lack of energy, even when physical health is relatively normal.

6. Chronic conditions: Certain chronic illnesses, such as fibromyalgia, autoimmune disorders, or chronic pain conditions, can contribute to ongoing fatigue and weakness.

It’s important to consult with a healthcare professional if you are experiencing persistent fatigue and weakness, as they can help identify the underlying cause through a comprehensive evaluation, including a medical history, physical examination, and possibly additional tests.