The constipation can cause dizziness or lightheadedness? In general I am dizzy when I can't go to the bathroom. Generally follows a period of diarrhea. Constipation can press the vagus nerve?
Anything is possible, but your symptoms indicate that you need a gastrointestinal study. The vagus nerve is too far away to be directly affected. Are you anemic? Sometimes, hypothyroidism can cause chronic constipation. Perhaps you should consult your doctor.