你有没有想过，为什么人老了会变矮？为什么有些人老了以后身高缩水那么多？怎样才能预防身高缩水？来看看专家怎么说。
人在成年之时，通常身高会达到顶点。但是你的身高会随着年龄而改变，年纪大了就会变矮，这并不是什么秘密。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.医学网站Medline Plus称，在40岁后每过十年人的身高通常会缩水1厘米左右，70岁后身高缩水速度会加快。总体来看，人在年老后身高会缩水1到3英寸（2.5到7.6厘米）。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.尽管人老了变矮是正常现象，但是有时候也预示着潜在的健康问题。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?从宏观层面来看，人在衰老时会因为骨骼、肌肉和关节的变化而变矮。美国贝勒医学院赫芬顿衰老研究中心的老年病学专家、副教授安吉拉·卡蒂克博士告诉雅虎生活频道：“有几种不同情况。”一种情况是，年纪大了以后，脊柱椎间盘所含的液体会减少。她指出：“脊柱椎间盘脱水后会变短，从而让你变矮。”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.卡蒂克说，另一种情况是，腹部肌肉随着时间流逝会衰弱，从而会导致驼背，让你看起来更矮。Abdominal muscles also tend to weaken over time, which can create a stooped posture, causing you to appear shorter, Catic says.健康机构Spectrum Health的内科医生艾拉什迪普·利特博士告诉雅虎生活频道，女性绝经会加速骨质流失，因为“雌性激素对骨骼的保护作用减弱了”，这也会令其变矮。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.但是利特指出，变矮也可能是由骨质疏松导致的，骨质疏松指的是骨密度和骨量下降，或骨骼质量或结构发生改变。美国国立卫生研究院称，这会降低骨骼强度，增加骨折风险。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那么，怎么知道是什么原因导致自己变矮的呢？利特说，如果你身高缩水总量超过1.5英寸（3.8厘米），你的医生就会怀疑你得了骨质疏松症。她指出：“身高缩水这么多是骨质疏松的迹象，需要进行骨密度测试。”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.这种测试可以测出你的骨强度，并确定你是否有骨质疏松症，以及未来发生骨折的风险。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年纪大了变矮一些是正常的。但是卡蒂克指出，你可以通过做以下几件事来降低身高缩水风险：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.避免吸烟、酗酒和过量摄入咖啡因，这些都是导致骨质疏松的风险因素Avoid smoking, excessive alcohol use and excessive caffeine intake — all of which are risk factors for osteoporosis.
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