There are many causes of vague pain in the upper right side of the head. It may be due to a headache in the brain due to ischemia or hypoxia. Insufficient blood supply to the brain can lead to a slight tingling pain in half of the head and a numb, swollen head. It may also be a vascular neurological headache, which can also cause a constant tingling sensation on one side of the head. Consider also diseases of the brain, such as brain infarction or having hemorrhagic lesions, which can cause prolonged pain in the head. It is also important to consider that the head will be vaguely painful if the head is infected with wind and cold due to improper warmth. In addition to these causes, there may be other causes of headache such as prolonged late night, concussion, cerebral arteriosclerosis, etc. It is recommended to go to the hospital immediately for head examination to determine the cause for proper treatment.