Been on bed rest for a month and concerned about passing out or throwing up once i get up. if it happens, should i call ambulance?

Vasovagal: When a person has been in bed for a prolonged period whether after a surgery, or for other reasons they are at increased risk for vasovagal syncope where they tend to get light headed and sometimes faint as a result of standing up too quickly. Take it very slowly at first. Have a friend or family member stay with you. If you experience a medical emergency, then of course, call 911.