Sleep problems dietary deficiencies (iron, vitamin B12, vitamin D), dehydration, or stress are some of the causes of feeling drowsy all the time. Chronic fatigue may also be caused by suboptimal sleep hygiene, a sedentary lifestyle, or underlying medical disorders like hypothyroidism. In addition to sedatives and antihistamines, sleepiness is an adverse effect of several medications. If excessive drowsiness is a problem for you, a doctor's prescription forWaklert 150mg (armodafinil) may help you stay awake. In order to get long-term remedies, it is crucial to discuss the underlying problem with a healthcare professional.