Hello! Thank you for the query. Such numbness usually appears due to skin nerve compression by too tight underwear or long travel. If any of this factors has been recently present, all you should do is to avoid them (loose underwear) and wait a week or two until the nerve will get back to normal (sometimes it does not). If you find any noodles like thing in the testis area, varicocele can give be the reason. If the numbness aggravates when coughing, hernia needs to be ruled out as well. Hope this will help. Regards.