Hi there..excessive daytime sleepiness is feeling sleepy in day even after having adequate or prolonged night sleep..causes of it include Disturbance of the body's circadian rhythm(e.g. jet lag, shift work), sleep disorders such as narcolepsy, sleep apnea, idiopathic hypersomnia,.. atypical depression, Tumors, head trauma, anemia, kidney failure, hypothyroidism, Drug abuse, biotin deficiency.. get complete blood count to rule out anemia(low hemoglobin) and tsh to rule out hypothyroidism done once.. consult your physician for excessive sleepiness treatment..