Sounds like it might be poor circulation, but you should really see a physician for an accurate diagnosis.
Yes. That is called Hypotension, or low blood pressure. See your doctor.
Yes, it's normal for an 18-year-old and a 57-year-old to be friends, as friendships can form across different age groups based on shared interests, values, and experiences. Such relationships can offer unique perspectives and insights, enriching both individuals' lives. However, it's important for both parties to maintain appropriate boundaries and ensure that the friendship is healthy and consensual.