Short answer
Trouble staying asleep is a form of insomnia, and it has many possible causes. The common ones named by NIH and sleep-medicine sources are alcohol, sleep apnea, needing to urinate, menopause night sweats, stress and the lighter sleep that comes with age. If it happens three or more nights a week for over three months, guidelines recommend cognitive behavioral therapy for insomnia as the first treatment.
It counts as insomnia
Insomnia is not only trouble falling asleep. The National Heart, Lung, and Blood Institute (NHLBI) defines it as trouble falling asleep, staying asleep, or getting good quality sleep. Its page, last updated in March 2022, calls insomnia chronic when it occurs 3 or more nights a week and lasts more than 3 months.
The American Academy of Sleep Medicine (AASM) says about 10 percent of people have chronic insomnia. An occasional bad night does not count. Stress is a common cause of those.
What alcohol does to the second half of the night
Alcohol fits this pattern closely. A 2013 review of the studies in healthy volunteers, published in Alcoholism: Clinical and Experimental Research, found that at all doses alcohol shortens the time it takes to fall asleep and makes the first half of the night more solid. Then it increases sleep disruption in the second half.
The National Institute on Aging (NIA) puts it plainly: alcohol will not help you sleep, and even small amounts make it harder to stay asleep.
Other causes worth ruling out
Sleep apnea. NHLBI lists insomnia and waking up often during the night to urinate among its symptoms, and notes insomnia is a more common apnea symptom in women.
Menopause. NIA says hot flashes, especially night sweats, and changes in mood can contribute to poor sleep.
Age. NIA says sleep tends to get shorter and lighter as you age, and you may wake up more often during the night.
Needing to urinate. MedlinePlus, from the National Library of Medicine, lists evening fluids, caffeine and alcohol among the causes.
What the guidelines recommend
For chronic insomnia, the American College of Physicians recommended in 2016 that all adults receive cognitive behavioral therapy for insomnia (CBT-I) as the initial treatment. The AASM's 2021 guideline gives CBT-I its only strong recommendation, and suggests clinicians not use sleep hygiene tips as the only treatment.
NHLBI describes CBT-I as a 6- to 8-week plan that can be done in person, by telephone or online. If wake-ups come with loud snoring, gasping or daytime sleepiness, ask your doctor about a sleep study.
Related questions
Is waking up once a night normal?
Brief awakenings become more common with age, according to the National Institute on Aging. It becomes chronic insomnia when it happens 3 or more nights a week for more than 3 months and cannot be fully explained by another health problem.
Does a nightcap help you stay asleep?
No. A 2013 review found alcohol at all doses increased sleep disruption in the second half of the night.
Is CBT-I the same as sleep hygiene?
No. Sleep hygiene is one part of it. The AASM's 2021 guideline suggests not using sleep hygiene alone to treat chronic insomnia.
Read next
Sources
- NHLBI: Insomnia, what it is, causes and treatment (updated 2022)
- American College of Physicians: Management of Chronic Insomnia Disorder in Adults, clinical practice guideline (2016)
- American Academy of Sleep Medicine: Behavioral and psychological treatments for chronic insomnia disorder in adults, clinical practice guideline (2021)
- Ebrahim et al., Alcohol Clin Exp Res: Alcohol and sleep I, effects on normal sleep (2013)
- National Institute on Aging: Sleep and Older Adults (reviewed 2025)
Published 2026-10-04 · Last checked 2026-10-04
Educational content, not medical advice. Made for the United States.