You may know that the brain cannot feel anything, if your right brain is injured in some way you may experience malfunctions or numbness on the left side of your body, numbness on the right side of your head could be a symptom of left brain injury/malfunctioning. Talk to a doctor or family member if you suspect something serious like stroke, its worth it to be safe, but also use your common sense, like kindd said, it could be just from waking up from sleeping on one side of your head, or it could be poor blood circulation, you decide. Good luck.
Truly speaking, can’t think of any disease process resulting in numbness in half of brain. Does it disturb your sleep also? Do you also have any numbness in the face also? Do you also have any headache along with it? What about any other symptom like tingling or weakness in the hands and feet? Do you have any problems in seeing also?
I feel that you should get yourself examined by a neurologist and try to pinpoint the exact cause of the same as you might need other tests like an MRI for a confirmatory diagnosis.
The only thing I can think of is numbness arising after a patient has woken up from sleep after an abnormal position of the head in which the head gets turned to one side while sleeping.
Please keep me posted. Pl reply to my questions too.
Kind Rgds.