What is a Bone Density Test

Bone density test is done on bones to check the risk of fracture and osteoporosis. It is also known as Bone Mineral Density Test which doctors do to measure the strength of bones.

It is a non invasive method to check the health of bone and risk of osteoporosis. The test is usually done on lower spine bones, bones of forearm and femur bone. Bone density test is done to determine the density of bones because denser the bones, lesser are the chances of bone fractures and breakage. Bone density means how much calcium and other minerals are stored in a segment of bone and this test determines that. Bone density peaks at around 30 years and after that there is a gradual decrease in bone mass.   

Patients of osteoporosis are advised to go for bone density test. Osteoporosis causes the bones of the body to become fragile and weak leading to fractures and severe disability. The test not only helps in predicting the risk of osteoporosis but it can be used to determine the course of treatment for patient undergoing osteoporosis treatment.

The bone density test is very similar to an X-ray but the exposure to radiation in this test is much lesser than a chest X-ray. There are various devices to measure the density of bone. Bone density test can be done on a Central device, where the person is required to lie on a platform while a mechanical arm, with the scanner, passes over the body. This arm emits X- rays and captures the images of patients’ bones around hip, spine or body and compares them to an average young adult.

The test can also be done through portable devices which are called Peripheral devices. These are available at pharmacies and they measure the bones of finger, wrist, kneecap, shin bone and heel. Tests done through these peripheral devices are not very expensive but they are not very accurate in accessing the risk of osteoporosis. Some patients are advised to go for detailed hip or spine scan, in case they have tested positive on peripheral device test. Tests done through a central device is very accurate but costly too.

Usually females over 40 years of age are at risk of osteoporosis but males can also have it. Frequent fractures, loss in height, long term steroid medication and drop in hormone levels are indicators of osteoporosis. Post menopausal women, with family history of hip fractures and those who have not taken estrogen after menopause are high risk group for osteoporosis. Sedentary lifestyle, alcohol intake, cigarette smoking, history of eating disorders like anorexia nervosa are some more factors which can cause osteoporosis.