Should I see a doctor if I have numbness?

Yes. Absolutely. It may be benign, but you need to find out if it is something serious.
Have it evaluated. Numbness can occur from various reasons. Some potential causes include vitamin deficiency, nerve damage, nerve compression, and alcohol over consumption, side effects of different medications, or as a result of different systemic medical conditions such as diabetes. Get evaluated by a professional to determine the diagnosis. Treatment is based on the diagnosis.