Premenopausal osteoporosis is a condition that usually affects teenagers and college-age women, especially those who engage in excessive exercise, those who are abnormally thin, and those who have amenorrhea, otherwise known as the absence of menstruation. Premenopausal osteoporosis is also more likely to affect women with a family history of osteoporosis, or women with a personal history of eating disorders or other diseases, such as kidney disease, celiac disease, thyroid disease, and connective tissue disorders. In addition, those who smoke or take specific drugs such as steroids, anti-seizure medications, certain chemotherapy drugs, and the blood thinner heparin are at an increased risk.
Postmenopausal osteoporosis is a condition in which decreased estrogen levels lead to increased bone resorption. As such, the risk of osteoporosis for women rises sharply after menopause, especially for white women and Asian women, as well as women with small, thin frames. Postmenopausal osteoporosis and senile osteoporosis are the two most common types of osteoporosis, the latter of which is a condition where osteoblasts gradually lose the ability to form bone, while osteoclasts continue to function perfectly fine. Eventually, bone resorption overtakes bone formation around the age of 80.
There are two types of osteoporosis that appear in children, namely idiopathic juvenile osteoporosis and secondary juvenile osteoporosis. Idiopathic juvenile osteoporosis is a rare condition in which there is no known cause of the disease. It most often develops just before the onset of puberty and can affect both prepubescent girls and boys. While most of the bone density may return during puberty, child sufferers will usually experience a lower peak bone mass as adults. Secondary juvenile osteoporosis, on the other hand, develops as a result of another condition and is far more common than its idiopathic counterpart. The diseases that can lead to this type of osteoporosis include anorexia nervosa, Cushing’s syndrome, cystic fibrosis, diabetes, homocystinuria, hyperparathyroidism, hyperthyroidism, juvenile arthritis, kidney disease, leukemia, malabsorption syndrome, and brittle bone disease.
Both idiopathic juvenile osteoporosis and secondary juvenile osteoporosis are very serious conditions because approximately 90 percent of an individual’s bone mass is built before the age of 18 to 20. It follows that children who lose bone mass during their prime bone-building years are at risk for long-term complications, especially fractures, walking difficulties, collapse of the rib cage, curvature of the upper spine, and prolonged pain in the back and extremities. That said, although juvenile osteoporosis may impair growth during the acute phase of the disease, most children do experience a complete recovery of bone tissue over time.
https://www.webmd.com/osteoporosis/guide/types-of-osteoporosis#1
https://www.bones.nih.gov/health-info/bone/bone-health/juvenile/juvenile-osteoporosis