Muscle weakness, or myasthenia, is a decrease in strength in one or more muscles. It is a common symptom of muscular, neurological and metabolic disorders. Muscular diseases, such as muscular dystrophy and dermatomyositis (disorder characterized by muscle inflammation), are common causes of muscle weakness.
Rating Newest Oldest. Best Answer: A doctor has a degree from medical school (4 years, either an MD or a DO) and has gone through residency (anywhere from 3 to 10 additional years of training). They are licensed to practice medicine or surgery (or both) independently, write prescriptions, etc.
Another difference between the practice of physician assistants and nurse practitioners is that a physician assistant must practice under the supervision of a physician.