Hello, there are several causes for excessive sleep, Stress, anemia, vitamin deficiencies, working hard or rotating shifts , or skimping on sleep in order to stay on top of a full-throttle, Excessive caffeine drinks in the late night, waking up till late night, Excessive using of phones, tablets, computers, boring life style, heavy weight, hypothyroidism, smoking drinking etc sleep disorders, such as sleep apnea, restless legs syndrome, or narcolepsy. Etc,, please consult a general physician and examined first for any detectable causes.