Bones are constantly changing throughout life. New bone is built in a process called formation. Old bone is removed in a process called resorption. As a person ages, more bone loss occurs than growth, the quality of the bone declines and the structure of the bone weakens. These conditions can lead to a condition known as osteoporosis.

Bones are made up of protein, collagen and calcium, which give bones their strength. Each bone in the body contains two types of bone – compact bone and spongy bone. Compact bone is found on the outer part of bones and is solid and hard. Spongy bone is found on the inside of bones and is filled with tiny holes, just like a sponge.

Osteoporosis means "porous bone." In osteoporosis, the outside walls become thinner and the holes in the spongy bone becomes larger. The first signs of osteoporosis are seen in bones that have a lot of spongy bone, such as the spine, hip and wrist. Fractures can lead to a decrease in quality of life, disability and have been linked to an increased risk of desk.

Risk Factors

  • Low calcium intake
  • Vitamin D insufficiency
  • Excess vitamin A
  • High caffeine intake
  • High salt intake
  • Aluminum (in antacids)
  • Alcohol (three or more drinks per day
  • Inadequate physical activity
  • Smoking (including secondhand smoke)
  • Falling
  • Being thin

Estrogen, a female hormone, plays and important role in bone health. Estrogen is made by the ovaries. Among its other functions, estrogen protects against bone loss. After menopause, the decrease in estrogen triggers a period of rapid bone loss in women that starts one year before the final menstrual period and lasts for about three years.


Osteoporosis may not cause any symptoms for decades, however signs and symptoms do occur as the disease progresses. As the spinal bones (vertebrae) weaken, they can fracture. Fracture in the front part of the vertebrae can result in curving of the spine or loss of height. This type of spinal fracture often causes no pain. Sometimes fractures of the spine causes pain that travels from the back to the sides


All women aged 65 years or older should have a bone mineral density (BMD) test. Women who are younger than 65 years and have gone through menopause should have a BMD test if they have had a bone fracture because of fragile bones, or have other risk factors such as rheumatoid arthritis, smoking, alcoholism, a history of hip fracture in a parent, or a body weight of less than 127 pounds.

Dual-energy X-ray absorptiometry (DXA) of the hip and spine is considered to be the most accurate BMD test available. During a DXA scan you lie down for 3-10 minutes while a machine painlessly scans your bones. A test score is given for each site measured.

  • a negative score means you have thinner bones than the average 30 year old woman
  • a positive score means you have stronger bones than the average 30 year old woman
  • a T-score at any site of -1 to -2.5 indicates a risk of osteoporosis
  • a T-score at any site of -2.5 or lower means osteoporosis

Treatment and Prevention

Medication - Various medications are used to treat osteoporosis and help reduct the risk of fractures. Medications differ in how they work, how they are taken and how often they are taken. They can be taken by mouth, with an injection, intravenously (IV), in a nasal spray or as a skin patch.

Lifestyle Changes - Build and keep as much bone as you can through exercise, good nutrition and staying healthy. Stop smoking and avoid secondhand smoke, reduce alcohol intake, and take steps to prevent falls.

Exercise - Exercise increases bone mass before menopause and slows bone loss after menopause. Bone is living tissue and exercise makes it grow stronger. Healthy adults need to exercise about 30 minutes per day most days of the week. Choose a weight bearing activity such as brisk walking. Yoga, pilates and Tai Chi can build endurance and improve balance and posture, thereby reducing risk of falls. Strength training is also good for bones.

Calcium and Vitamin D - Calcium is important to building and maintaining healthy bones. Vitamin D helps the body absorb calcium. To increase your daily levels of calcium, eat a variety of calcium-rich foods. Good sources include dark leafy greens, like spinach, kale and collards; dairy foods, such as yogurt, milk, and cheese; and canned fish with bones, including salmon and sardines. You can increase your vitamin D intake by eating foods fortified with D (orange juice, cereal and milk). You can also get vitamin D by enjoying 15 minutes in the sun a few days per week. Calcium and vitamin D supplements are also available.

Jeffrey Harris MD