Who Treated the sick during the Middle Age?

There were a variety of people who might treat the ill.

Physics or Doctors

Firstly, if you were rich you might see a physic or a doctor.  A physic is the old name for a doctor.  They were highly educated, especially in the classical ideas of Hippocrates and Galen.  Most of their training was theoretical and based on reading books and studying at University.  Because they were University Educated they were all men; women were not allowed to go to university.

Apothecaries

Today we would call Apothecaries chemists and a doctor could well send you to one for treatment.  They mixed remedies and potions to treat illnesses/they were mainly herbal remedies, but they would also prescribe poisons.  Most apothecaries were trained as apprentices and had to join the guild when they qualified.  The guild regulated how they traded.

Surgeons

Surgeons or barber surgeons were not as important as doctors, this is very different from today.  Barbers were trained to do minor operation and dentistry as well as cut hair. Like apothecaries they were trained as apprentices and in sometimes could be women.

Midwives and wise-women

Midwives were important for helping women through childbirth and were licensed by the local Bishop.  Wise-women were not formally trained or licensed but were taught, often by their mothers and their ideas were handed down through the generations.  Also like today for most people, the first point of medical contact was Mum who would use tried and tested family treatments.

Hospitals

Hospitals is an interesting one; hospital or hospitality is really to do with giving someone board and lodgings for a night and not medicine.  Hospitals were often attached to monasteries and were places for travellers to stop.  However, during the Middle Ages they started to develop  into places for treating the sick.  They were often small and were run by religious groups so a main form of treatment was to pray for you.  The famous London Mayor, Dick Whittington set up for unmarried pregnant women St Thomas's Hospital for unmarried pregnant women; which is still going today. Lepers were sent to Lazar houses often called Leper Colonies.

Finally; I advise you try to find out about the Regimen Sanitatis - have a look at it and see if you think much of it is still good advice.