Why do older adults often have more difficulty falling and staying asleep than younger people?

Elder sleep problem: Anxiety leads to difficulty to initiate sleep, depression leads to prob maintaining sleep. Elders may deny any problem, which may be real, or which problems accumulate in life (no matter whether you remember your previous stresses but the sub-conscience never forgets and life accumulated stress stagger up). Sedentary life leads to sleep problem. Healthy lifestyle till death.

Sleep: As one gets older, sleep naturally begins to fragment and 'advance' to an earlier time on the night. As a result, older individuals take more naps in the day. Additionally co-morbidities come into play such as painful joints, mood disorders and anxiety, sleep apnea, waking up to use the restroom at night or to get water, etc.