Why do I want to sleep when I sit down during the day? This question may have different answers for different people, mainly due to the following reasons: first, seen in the early stages of some diseases, such as Alzheimer’s disease, Parkinson’s disease can cause the above symptoms; second, mainly seen in the cerebral artery blood supply deficiency, some elderly people due to long-term hypertension, atherosclerosis, coupled with the age factor leading to cerebral arteriosclerosis, cerebral blood supply can not keep up, so the phenomenon of daytime when sitting down Third, the patient may have episodic sleep changes and fall asleep soon after sitting down for a few minutes; fourth, the patient may not get enough sleep at night and make up for it through short sleep during the day.