Risk factors for osteoporosis include:

• Sex: Women are at least twice as likely to have osteoporosis as men because they have less bone mass to begin with and lose bone mass faster than men as they age. About 1 out of 5 American women over the age of 50 have osteoporosis.
• Age: The older you are, the greater your risk of osteoporosis. The longer it has been since your bone density peaks in your thirties, the thinner and weaker your bones become.
• Body size: Small, thin-boned people (especially women) are at greater risk.
• Ethnicity: Caucasian and Asian women are at highest risk while African American and Hispanic women have a lower risk.
• Family history: People who have close relatives with low bone mass, osteoporosis, or a history of fractures may be at higher risk.
• Sex hormone levels: Low estrogen levels in women and low testosterone levels in men can bring on osteoporosis. It is lifetime exposure that matters so women with infrequent menstrual periods or early menopause are at increased risk.
• Calcium and vitamin D intake: A diet low in calcium and vitamin D makes you more prone to bone loss and osteoporosis.
• Medications: Long-term use of corticosteroids can lead to loss of bone density.
• Lifestyle: a sedentary lifestyle or extended bed rest causes reduced bone mass.
• Cigarette smoking: Cigarettes increase the risk of bone problems.
• Alcohol intake: Excessive alcohol consumption increases the risk of bone loss.
• Having osteopenia: Osteopenia is like pre-osteoporosis and often progresses to become osteoporosis unless it is treated.