Dr. John Grieveson graduated from Ponce School of Medicine in Puerto Rico in 1990 and did his residency in Family Medicine at the Reading Hospital in Pennsylvania. He moved to Lowell, Massachusetts in 1996, working for the Saints Medical Center on Merrimack Street. In 2009, he started his own practice and has continued to serve children and adults of all ages.

Based on the family medicine model of holistic approach, he emphasizes first on prevention and good maintenance of chronic illnesses by making patient care a team approach between the patient, their family, and the doctor to obtain best results. He firmly believes that a patient should make their own medical decisions after obtaining adequate counseling in terms of their choices for care. He also encourages them to change their lifestyle for their own benefit in the long-run.