In the clinic, the elderly fall to the head, in general, within two weeks is a dangerous period, but it should be noted that in about a month is also a relatively dangerous period, the details are as follows: 1, within two weeks: in general, after the elderly fall to the head, many times may occur delayed intracranial hematoma, and delayed intracranial hematoma within two weeks has the greatest chance of occurring. Therefore, after an elderly person falls on the head, he or she must promptly undergo head CT testing to clarify the intracranial changes, even if there is no bleeding and other signs, but in about 7-10 days must be re-examined again CT to exclude the case of delayed intracranial hematoma. 2, about a month: about a month is easy to form a chronic subdural fluid, the same need for the corresponding review, in order to finally clarify the specific diagnosis.