Osteoporosis happens when bones lose mineral density, making them weak and fragile, which increases the risk of fractures. It's helpful to understand the different terms doctors use for osteoporosis, based on when it starts or what causes it. Treatment depends on the type of osteoporosis a person has.

Osteopenia

Osteopenia is when bones get thinner, but not enough to be considered osteoporosis. Both osteopenia and osteoporosis are diagnosed using a test that measures bone mineral density. The most common test is called dual-energy X-ray absorptiometry (DXA). A DXA scan provides results such as bone mineral density and T-score, which compares your bone density to the highest possible value.

Thresholds for T-scores are defined as:

• Minus 1 or above – Normal
• Lower than minus 1 and greater than minus 2.5 – Osteopenia
• Minus 2.5 or lower – Osteoporosis

If you have osteopenia, you’re at significant risk of developing osteoporosis.

Primary Osteoporosis

Osteoporosis that doesn’t have a direct cause but occurs with aging is described as primary osteoporosis, and it’s the most common type. There are two subtypes — type 1 and type 2.

Type 1 osteoporosis is much more common in women, according to Mayo Clinic, which is why it’s also called postmenopausal osteoporosis. It usually develops between ages 50 and 70, when estrogen’s protective effects begin to fade because hormonal levels drop with age. Wrist and spine fractures are common in type 1.

Type 2 osteoporosis, also called senile osteoporosis, develops after age 70. In type 2 osteoporosis, hip and spine fractures are the most common.

There can be some overlap between types 1 and 2 osteoporosis.

Secondary Osteoporosis

When osteoporosis is caused by another health condition or medical treatment, it’s called secondary osteoporosis. Conditions such as kidney failure, leukemia, and thyroid disease can lead to osteoporosis. Medications that can cause osteoporosis include corticosteroids such as prednisone, some breast cancer medications, and depot medroxyprogesterone acetate (Depo-Provera), a birth control injection. Secondary osteoporosis caused by medication can sometimes be reversed if it’s caught early and the drug causing it is stopped or preventive treatments are used.

Rare Types of Osteoporosis

Osteoporosis related to pregnancy is rare and happens when an otherwise healthy person develops fractures as a result of lower bone mineral density during pregnancy or shortly after childbirth. These fractures can cause severe pain and usually affect the spine or hip. It’s unclear why osteoporosis develops during pregnancy, but most people who develop it fully recover.

Osteoporosis can occur in children. Secondary osteoporosis is the most common type and may be caused by conditions such as anorexia nervosa and leukemia or by medications used to treat other health problems. Children also may develop osteoporosis due to rare genetic conditions such as osteogenesis imperfecta (caused by defective collagen production) and osteoporosis pseudoglioma syndrome (caused by abnormal bone and eye development). When osteoporosis in children occurs with no clear cause, it’s called idiopathic juvenile osteoporosis, which is extremely rare.

Transient migratory osteoporosis can cause severe pain and fractures in one part of the body and then later in another part. For instance, a person with transient migratory osteoporosis may have a fracture and pain in one hip, and then later experience pain and a fracture in one foot. Bone mineral density scans usually appear normal in unaffected areas but show a loss of density in the area with symptoms. Transient migratory osteoporosis is also known as bone marrow edema syndrome.

Talk With Others Who Understand

MyOsteoTeam is the social network for people with osteoporosis and their loved ones. On MyOsteoTeam, more than 62,000 members come together to ask questions, give advice, and share their stories with others who understand life with osteoporosis.

Have you been diagnosed with osteoporosis? Which type do you have? Share your experience in the comments below, or start a conversation by posting on your Activities page.