 "How many hours of sleep do you need at each age? A doctor's guide")
“Eight hours of sleep is non-negotiable.” But sleep is not a one-size-fits-all prescription. It changes with changes in the brain, hormones, and internal body clock, even without us realising it. So how much sleep do we actually need at different stages of life, and when should we worry that we’re not getting enough?
Why does sleep need change with age?
Sleep changes because we change neurologically, hormonally, and biologically. According to Dr Pradeep Bajad, Senior Consultant in Pulmonary, Critical Care & Sleep Medicine at Amrita Hospital, Faridabad, early life is dominated by brain growth. Infants and young children spend far more time in deep and REM sleep because their brains are rapidly wiring themselves.
As we move into adolescence, the circadian rhythm, the body’s internal clock, shifts later. Teenagers aren’t being rebellious when they stay up late; their biology is nudging sleepiness towards midnight and beyond.
Adulthood brings more consolidated sleep, but with ageing, deep sleep and REM (Rapid Eye Movement) sleep gradually decline. Older adults don’t stop needing sleep; their sleep simply becomes lighter, shorter, and more fragmented.
In simple terms:
- Young brains need sleep to grow
- Adult brains need sleep to function
- Older brains still need sleep, but struggle to hold on to it
How many hours of sleep are recommended at different ages?
According to Dr Bajad, here are the healthy ranges for age-wise sleep needs:
- Newborns (0–3 months): 14–17 hours
- Infants (4–11 months): 12–15 hours
- Toddlers (1–2 years): 11–14 hours
- Preschoolers (3–5 years): 10–13 hours
- School-age children (6–12 years): 9–11 hours
- Adolescents (13–18 years): 8–10 hours
- Young adults (18–25 years): 7–9 hours
- Adults (26–64 years): 7–9 hours
- Older adults (65+ years): 7–8 hours
How reliable are age-based sleep recommendations?
Dr Bajad says that sleep guidelines are evidence-based, but they aren’t commandments carved in stone.
“Age-wise sleep guidance come from long-term population studies, lab research, and real-world health outcomes. Indian and global sleep panels consistently avoid exact numbers as human sleep varies widely. What matters most is not whether you hit a perfect number, but whether reduced sleep is paired with daytime dysfunction such as poor concentration, emotional volatility, metabolic issues, or declining cognition. If none of these are present, your sleep duration and pattern may simply reflect individual biology.”
Do older adults need less sleep?
Older adults don’t need less sleep; they often get worse-quality sleep.
With age comes frequent night-time awakenings, earlier morning waking, and reduced deep sleep. So while an older person may technically clock seven hours, that sleep may be fragmented and less restorative.
Indian geriatric studies link such broken sleep to poorer glucose control, higher blood pressure, mood changes, and an increased risk of falls, even when total sleep time appears “adequate”.
What happens when you consistently get less sleep than your age needs?
“The consequences are different at different stages of life,” says Dr Bajad. According to him:
In children and teenagers, chronic sleep loss interferes with attention, learning, emotional regulation, and impulse control. Indian school-based studies associate short sleep with higher anxiety, irritability, academic struggles, and obesity.
In working-age adults, insufficient sleep disrupts metabolism, raises blood pressure, worsens insulin resistance, and fuels anxiety and depression. Urban Indian data increasingly link short sleep with diabetes, cardiovascular disease, and burnout.
In older adults, poor sleep accelerates cognitive decline, weakens immunity, increases fall risk, and worsens chronic pain. Even mild but persistent sleep loss can impair memory and reaction time.
“Remember, sleep debt doesn’t magically disappear after a long weekend lie-in,” stresses Dr Bajad.
How do lifestyle and environment affect sleep across life stages?
Screens suppress melatonin, especially in children and teens. Academic pressure pushes Indian adolescents into chronic sleep deprivation. Shift work scrambles the adult body clock, raising cardiometabolic risks. Menopause introduces night sweats and frequent awakenings. Chronic pain and medications commonly fragment sleep in older adults.
In these situations, Dr Bajad says, “enough sleep” may mean better timing, better quality, or targeted treatment, and not just counting hours.
How can you tell if you’re getting enough sleep for your age?
Feeling tired isn’t the only clue. Warning signs include needing caffeine to function, mood swings, poor stress tolerance, frequent infections, headaches on waking, or sleep that doesn’t feel refreshing.
In older adults, red flags may show up as balance issues, falls, or episodes of confusion.
If these symptoms persist despite “adequate” sleep duration, the issue may lie in sleep quality or an underlying disorder such as sleep apnoea, insomnia, or circadian rhythm disruption. That’s when medical evaluation matters.
“Listening to those signals, and understanding what’s normal for your stage of life, can be one of the simplest, most powerful health decisions you make,” Dr Bajad says. For more health updates, follow #HealthWithBS
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This content is for informational purposes only and is not a substitute for professional medical advice.