Osteoporosis, a disease that causes bones to weaken and sometimes break, is often thought of as a "women's disease," but it poses a significant threat to more than 2 million men in the United States, according to the National Institutes of Health.
After age 50, 6 percent of all men will experience a hip fracture and 5 percent will have a spinal fracture as a result of osteoporosis, NIH has reported.
Osteoporosis in men "is an area, you could say, that's forgotten almost," said Bob Schmaltz, radiology assistant with Altru Health System in Grand Forks, N.D.
About 12 million American men are at risk of osteoporosis, he said.
Schmaltz performs Dexa scans, dual-energy X-ray absorptiometry, a technology that measures bone mineral density, or BMD.
The scans focus on the spine and hip, which is where most osteoporosis-related fractures occur, he said.
Osteoporosis is considered to be a "silent disease," Schmaltz said. "You don't know you have osteoporosis until you're well into the disease."
In men, the diagnosis is often not made until a fracture occurs or a man complains of back pain and sees his doctor.
"Men at age 70 should be scanned," Schmaltz said. "I don't see that happening in our practice. We're not seeing a glut of males" coming in for a scan.
On average, he scans 10 patients a day, he said. "I have not seen a male in about two months."
In recent years, recognition of male osteoporosis as an important public health issue has grown, particularly in light of estimates that the number of men older than 70 will continue to increase as life expectancy continues to rise.
Several reasons explain why men have a lower risk of osteoporosis.
Because women live longer, they are more likely to get the disease, Schmaltz said. "There are four times as many women who have osteoporosis than men."
Lifestyle may also be a factor in protecting men from osteoporosis.
"Generally - and I'm speaking` generally now - men are more physically active during their lives," he said. "They're engaging in heavier work."
Physical activity and weight-bearing exercise have been shown to play an important part in building and maintaining bone density.
But some lifestyle behaviors, such as extensive alcohol use and smoking, contribute to their risk.
"Smokers have a higher rate of fractures," Schmaltz said. "They have a 55 percent higher risk for hip fractures compared to nonsmokers."
People who use nicotine and caffeine excessively and "couch potatoes" tend to have lower bone mass than those who don't, he said.
The most common cause of male osteoporosis is testosterone deficiency, an area that needs more scientific attention, Schmaltz said, based on studies he's read.
More men who have this condition should be evaluated by bone density scans, he said.
Several medications - such as steroids and drugs for prostate cancer and seizures - can affect bone mass, he said.
"A lot of times, someone who's taking medications for prostate cancer or metastatic disease elects not to have surgery," he said. "We get a baseline (Dexa scan) to start with."
If later scans reveal that medications are causing major bone loss, a change in treatment may be considered, he said. Doctors "don't want to create another problem."
Conditions such as rheumatoid arthritis, digestive and blood disorders, and cystic fibrosis play a role in developing osteoporosis, Schmaltz said. They can impair the body's ability to absorb needed nutrients.
Bone loss is a common side effect of drugs used to treat asthma and rheumatoid arthritis, according to the NIH.
Men have larger skeletons, their bone loss starts later and progresses more slowly, and they have no period of rapid hormonal change and bone loss, as women do after menopause, according to the NIH.
Bone is constantly changing - that is, old bone is removed and replaced by new bone. During childhood, more bone is produced than removed, so the skeleton grows in both size and strength.
"Bones, if they're healthy, are very, very strong," Schmaltz said.
For most people, bone mass peaks during their 20s. By this age, men typically have accumulated more bone mass than women. After this point, the amount of bone in the skeleton typically begins to decline slowly as removal of old bone exceeds formation of new bone.
"Bone continually monitors what stress we put on it," he said. "With bone mass, it's a 'use-it-or-lose-it' proposition, much like muscle."
But by age 65 or 70, men and women are losing bone mass at the same rate, and the absorption of calcium - an essential nutrient for bone health throughout life - decreases in both sexes, the NIH said. Excessive bone loss causes bone to become fragile and more likely to fracture.
Most commonly, fractures occur in the hip, spine and wrist, and can be permanently disabling. Hip fractures are especially dangerous. Perhaps because such fractures tend to occur at older ages in men than in women, men who suffer hip fractures are more likely than women to die from complications, according to the NIH.
Early detection of a loss in bone density can alert your doctor to the need for medication or supplements, a balanced diet with a lot of calcium- and vitamin D-rich foods, a program of physical exercise and smoking cessation.
Exercise - such as brisk walking at least 30 minutes a day - is a proven method to strengthen bones, Schmaltz said. And any weight-bearing exercises are helpful.
"In the 25 to 64 age range, only about 35 percent of men are meeting the minimum exercise prescription of what they should be doing," he said.
Calcium is critical to helping the body build and maintain bone density.
"To make new bone the body needs, it takes plenty of calcium," Schmaltz said. "In the age range of 19 to 50, it's recommended that a person get 1,000 milligrams a day. If you're older than 50, the recommendation is 1,200 milligrams a day."
To help the body properly use calcium, vitamin D is recommended, he said. "The recommendation used to be 400 to 800 (international) units a day; now it's 800 units a day. Some take 1,200."
Some health professionals are including the Dexa scan in their male patients' annual physical exam, Schmaltz said. "They'll tell the patient, 'We'll check your BMD along with your hemogloblin and cholesterol.'
"It's better to be proactive than waiting for something to happen."
Explore further: Experts recommend men at risk for osteoporosis undergo bone density testing