Bones play a major role in the human body. We tend to lose bone strength as we age. But still, with adequate care and a healthy lifestyle, we can avoid the risks of many bone related issues in old age.

Factors influencing bone health and causing degeneration as you age :
Imbalanced Diet - eating unhealthy food which contains less or insufficient Calcium, Vitamin D and Proteins. Vitamin D assists with absorbing calcium in the body. Calcium is required to maintain bones and teeth in good condition and proteins help in maintaining muscle strength. 
Excessive consumption of alcohol and tobacco - As per research, the risk of getting a bone problem is much higher in people consuming alcohol and tobacco in very high quantities. 
Physical Inactivity - Sitting in one place for a longer time, not doing any physical exercise at least 2-3 times a week increases the risk of damaging bones.
Hormones Imbalance - A consistent rise in thyroid hormone level can result in bone damage.
Hormones Imbalance - A consistent rise in thyroid hormone level can result in bone damage.
Natural Reasons - Age, Sex and weight can affect bone health. As we get old, bones become weak. Women are more prone to bone problems than men. Obesity increases the risk of having bone damage.
Family History - Sometimes family history and genetics may also cause bone damage.
High Dosage Of Medications - Prolonged use of certain medications used in the treatment may also cause damage to bones