What social factors had a negative impact upon the health of ordinary people during the period 1250-1500?

The Early Modern Age saw advances in theory, but not in practice. The most advanced Early Modern physicians were usually town-based, and also:

were well educated and trained

did 'scientific' research

were prepared to contradict the accepted authority

disseminated their findings

relied on royal support

had limited success

However, they charged very high fees and only the richest people could afford them.