It is normal to feel tired after a hard work period. However, when fatigue persists for a long time even when you have not done anything, nothing signals something else.
There are many reasons why you may feel tired, and some of them may require medical attention.
Anemia
In anemia, the body does not produce enough red blood cells, which can cause fatigue and weakness. The possible causes of anemia are many, but it usually comes from a lack of iron or vitamin B12. Anemia is diagnosed with a simple blood test.
Obstructive sleep apnea
Obstructive sleep apnea is characterized by repeated episodes of cessation of breathing during sleep, caused by a blockage of the upper airway. Apnea leads to poor sleep quality and daytime fatigue.
Depression
Depression can cause a variety of physical symptoms, such as fatigue and low energy levels.
Thyroid problems
Both an overactive thyroid and an underactive thyroid can cause fatigue and other symptoms.
Signs that you may have a thyroid problem include:
Sensitivity to cold or heat
Weight gain or loss
Depression and mood swings
Muscle pain and weakness
Diabetes
High blood sugar levels can cause fatigue, as well as other symptoms such as extreme thirst and frequent urination.
Fatigue can also be the result of other lifestyle factors, such as poor diet and dehydration. A diet high in sugar, processed foods and unhealthy fats can make you feel tired and sluggish.