Thanks for using the forum. I am happy to address your questions, and my answer will be based on the information you provided here. Please make sure you recognize that this forum is for educational purposes only, and it does not substitute for a formal office visit with a doctor.
Without the ability to examine and obtain a history, I can not tell you what the exact cause of the symptoms is. However I will try to provide you with some useful information.
One-sided numbness (i.e., face and hand) is most commonly due to a problem in the brain (as opposed to other areas of the central nervous system such as the spinal cord or peripheral nerves). Many possibilities exist, and depend somewhat on your age, your risk factors, and the nature of your symptoms (whether or not the numbness started suddenly or gradually, whether it is a complete loss of sensation or a tingling, whether it is an objective finding on examination or it is only a feeling that you have etc).
The most concerning cause of numbness on one side of the body is a stroke, as you mentioned. Please understand I am not trying to imply you have a stroke, but only that this is one possibility. Strokes occur predominantly in people with risk factors: smokers, high cholesterol, diabetics, hypertensives, and people over the age of 55. However, they can occur in any age. If your numbness was due to a stroke, it would start somewhat suddenly (over minutes) and would likely persist without significant improvement. However, there are “mini” strokes (i.e., transient ischemic attacks) which are vascular events that resolve without structural damage.
Other potential causes include multiple sclerosis, a brain tumor, a vascular malformation and others. Lastly, transient one-sided body numbness (lasting for example for minutes up to 30 minutes then resolving) could be due to a migraine (the aura of migraine, in which case following the numbness, a headache occurs) or seizures (which would be important to evaluate given the prior stroke history).
These are a few causes of one-sided numbness (excluding focal hand numbness, which could be something called carpal tunnel syndrome, for example).
I suggest that you be evaluated by a physician and perhaps eventually by a neurologist. Depending on your history and physical examination, he/she may choose to order an MRI of the brain, which would be able to assess for several of the disorders discussed above.
Thank you for this opportunity to answer your questions, I hope you find the information I have provided useful, good luck.