Heart disease
According to research, one of the most common causes of persistent fatigue or uncontrollable urge to go back to bed after waking up is disruption of the heart or blood vessel function. People who have diabetes, high blood cholesterol, obesity or smoke are more susceptible to lung or heart disease.
In some cases, persistent fatigue may be caused by cancer treatment. While fatigue caused by cancer usually leaves after a year, studies show that about 25 to 30 percent of people still feel severe physical and emotional fatigue a few years after treatment.
According to research, fatigue caused by cancer may occur due to disruption in your immune system, nervous systems, and inflammation. This type of fatigue can be treated with acupuncture, yoga, mindful techniques, psychotherapy, and physical exercise.
Thyroid disorders
Persistent tiredness can also be caused by thyroid conditions like hypothyroidism [5], Hashimoto’s disease (also called Hashimoto’s thyroiditis) [6]. This feeling of tiredness can persist for months or years if the thyroid disorder is not treated properly.
The function of your thyroid can also be disrupted by heart drugs and bipolar disorder. Hyperthyroidism can be caused by certain cancer treatments. You can treat an underperforming thyroid with drugs that can replace hormones.