One of the earliest changes people notice is disrupted sleep.
After 70, the brain produces less melatonin—the hormone responsible for deep, restorative sleep. At the same time, the body’s internal clock becomes more sensitive to light and sound.

As a result:

• Nighttime awakenings become more frequent
• Falling back asleep takes longer
• You may feel tired despite spending many hours in bed
• This isn’t classic insomnia. It’s a natural neurological shift associated with aging.

Helpful habits

• Get morning sunlight
• Limit bright screens in the evening
• Keep consistent sleep and wake times

2. Temperature regulation becomes less reliable

After 70, the body’s ability to manage heat and cold weakens. It adapts more slowly to temperature changes, which is why older adults often:

• Feel cold more easily
• Overheat faster
• Sweat less, making cooling harder
• This isn’t just uncomfortable—it raises the risk of heat exhaustion or hypothermia.

What helps

• Wear layers, even indoors
• Avoid extreme heat or cold
• Stay well hydrated

3. Digestive changes become common