The most common factors for headaches when waking up from an afternoon nap are as follows: 1. Cerebrovascular diseases usually cause headaches when waking up from an afternoon nap due to cerebral artery supply deficiency, vertebrobasilar artery stenosis, and internal carotid artery stenosis resulting in cerebral vascular ischemia, which can lead to cerebral infarction, cerebral infarction, and extreme large artery supply insufficiency syndrome. 2. A history of cervical spine disease can also cause headaches when waking up from an afternoon nap, which is often due to The second to seventh intervertebral discs of the cervical spine are herniated or bulged, compressing the arteries and nerves therein and causing nerve root numbness and edema, leading to headache symptoms. 3. headache when waking up from an afternoon nap is also caused by brain ischemia and lack of oxygen, usually caused by lack of oxygen in brain cells, decreased arterial oxygen saturation, increased partial pressure of carbon dioxide, and low partial pressure of oxygen causing brain hypoxia and headache. 4. headache when waking up from an afternoon nap is caused by the precursor symptoms of cold. Waking up with a headache.