I have sharp head pains and now lower back pain when I stand for too long should I e worried? Are they related? What can it be?

Maybe, maybe not. Mysterious pain symptoms can be evaluated by a primary care doctor, who may then refer to various specialists for more evaluation. For back and head pains, many, many reasons exist. Sometimes there are problems with the positions of the vertebrae, or some muscle strains/tightness in the neck or back, or past injury effects, or overuse damage, or nerve compression, internal diseases, etc., etc....