Once you become an adult, you typically reach your full height. But your height can change with age, and it's no myth — you shrink with time.
People usually lose about a centimeter in height every 10 years after age 40, according to Medline Plus, and that pace of height loss speeds up after age 70. Overall, you can lose between 1 to 3 inches in height as you age, per Medline Plus.
While age-related height loss is normal, there are times when it's a sign of an underlying health condition.
Why do you get shorter as you age?
On a macro level, you get shorter as you age due to changes in the bones, muscles and joints. "There are a few different things going on here," Dr. Angela Catic, a geriatrician and associate professor in the Huffington Center on Aging at Baylor College of Medicine, tells Yahoo Life. One, she says, is that the discs between the vertebrae in your spine lose fluid as you get older. "They become dehydrated and, with that, they lose height — and you lose a bit of height," she says.
Abdominal muscles also tend to weaken over time, which can create a stooped posture, causing you to appear shorter, Catic says.
In women, menopause can speed up bone loss "due to the loss of the protective effects of estrogen on bones," Dr. Arashdeep Litt, an internal medicine physician with Spectrum Health, tells Yahoo Life. That, too, can cause you to get shorter.
But height loss can also be due to osteoporosis, a bone disease that develops when bone mineral density and bone mass decreases, or when the quality or structure of bone changes, Litt says. That can decrease your bone strength and increase your risk of fractures, according to the National Institutes of Health (NIH).
How to tell the difference between normal height loss and signs of osteoporosis
So, how can you know what's behind your shrinking size? Your doctor will suspect osteoporosis if you have an overall height loss of 1.5 inches or more, Litt says. "This much height loss is a sign of osteoporosis and warrants a bone density test," she says.
The test can tell how strong your bones are and will determine if you have osteoporosis, as well as your risk of fractures in the future.
How to prevent height loss
Again, some height loss is normal. But Catic says you can lower your risk of height loss by doing the following:
Lift weights (this, along with regular exercise, stresses your bones and makes them stronger).
Eat a diet rich in calcium and vitamin D to support bone health.
Avoid smoking, excessive alcohol use and excessive caffeine intake — all of which are risk factors for osteoporosis.