1. Medical doctor (M.D.)

2. Doctor of osteopathic medicine (D.O.)

3. Doctor of public health (Dr.P.H.)

4. Doctor of philosophy (Ph.D.)

5. Doctor of nursing practice (D.N.P.)

6. Doctor of physical therapy (D.P.T.)

7. Pharmacist (Pharm.D.)

8. Veterinarian (D.V.M.)

9. Doctor of health science (D.H.Sc.)

10. Computer scientist (DCompSci)

11. Podiatrist (D.P.M.)

12. Audiologist (Au.D.)

13. Engineer (DEng)

14. Doctor of social work (DClinP)

15. Doctor of arts (D.A.)

16. Doctor of psychology (Psy.D.)

17. Doctor of musical arts (D.M.A.)

18. Doctor of health administration (D.H.A.)

19. Doctor of business administration (D.B.A.)

20. Doctor of public administration (D.P.A.)

21. Doctor of music education (D.M.E.)

22. Doctor of design (DDes)

23. Lawyer (J.D.)

24. Doctor of fine arts (D.F.A.)

25. Theologist (S.T.D. or Th.D)

26. Doctor of Hebrew Letters (D.H.L.)

27. Doctor of Canon Law (J.C.D.)

28. Dentist (D.D.S.)

29. Optometrist (O.D.)

30. Doctor of management (D.M.)

31. Doctor of ministry (DMin)

32. Chiropractor (D.C.)

33. Being hit by a car

34. Doctor of education (Ed.D.)

(Rankings based on U.S. standards.)

Photo credit: AP