You might feel that it’s harder to focus and remember
things. But most people think their memory is worse than
it really is. The same goes for concentration. Your risk of a
traffic accident or other injury may be higher (see Drowsy
Driving). You may be more emotional and a lack of sleep
can cause depressed mood. Some people feel sleepy
during the day, but this can be caused by many things
(see Excessive Daytime Sleepiness).