Common signs of low bone density include cramps, pain, deformities and fractures. 1. Cramp: Low bone density may cause cramp, which is due to the fact that most of the patients with low bone density will be accompanied by calcium deficiency, which is easy to make the soft tissues such as muscles and fascia contract involuntarily beyond the normal range of the fascia and lead to cramp. 2. Pain: Osteoporosis is common in low bone density, with generalized bone pain as the main cause, mostly in weight-bearing parts, which occurs in winter or spring when there is less sunlight. 3. Deformity: low bone density is also easy to lead to osteochondrosis, after the decline in bone strength can lead to deformation of bones, such as hunchback or short height, some of the older people will find their height is getting lower and lower, in fact, the reduction in height is the more common hidden symptoms of low bone density. 4. Fracture: Brittle fracture is common, and the fracture may occur when there is a small trauma, and the common parts are wrist, shoulder, hip and spine. Especially in the middle-aged and old-aged groups, if the above symptoms occur, low bone density should be highly suspected, and it is recommended to go to the hospital for bone density test in time.