The common causes of brittle bones are as follows: 1. It may be caused by osteoporosis. This condition is the most common in clinical practice, and the causes of osteoporosis are diverse, including malnutrition, long-term braking, changes in hormone levels in the body, or long-term application of glucocorticoids. 2, may be caused by the patient’s own genetic disorders. For example, hereditary factors lead to osteogenesis imperfecta, which is often referred to as porcelain doll. This type of patient can cause pathological fractures after a slight external force. 3, may be caused by environmental factors. If the fluoride content in the water is abnormal, then the bones may become brittle. 4. This condition may also be caused by malignant tumors in the body. If a patient has a malignant bone tumor or a bone metastasis from the tumor, then the strength of the bone will also be greatly reduced.