Think of an oncologist as your main physician for cancer care. After being diagnosed, you’ll meet regularly with an oncologist to explore and manage your treatment options, as well as monitor your condition throughout the process. Medical oncologists are extremely knowledgeable in various types of cancer treatment and can recommend the right method for the type and stage of cancer you’re facing.
They may also refer you to additional specialists throughout your care, but they will always be your home base for questions and support. It’s also worth mentioning that medical oncologists deal mostly with solid tumors while hematologists specialize in cancers that involve blood disorders, such as leukemia.

An Oncologist is a physician who focuses on the diagnosis and treatment of different cancers. This physician has extensive knowledge of the different signs and symptoms of cancer, as well as the various methods of treatment.
Oncologists diagnose cancer through methods such as biopsy, endoscopy, X-ray, blood tests, ultrasound, and different forms of nuclear medicine. They treat cancer through surgery, chemotherapy, radiotherapy, hormone therapy, or antibody treatments.
If it is determined that a cancer cannot successfully be treated, oncologists then focus on providing palliative care, the use of pain medication to make a dying person more comfortable.

A rheumatologist is a physician who has received extensive training in diagnosing and treating rheumatic conditions. Rheumatic conditions involve the joints, soft tissues, autoimmune system, vascular system, and connective tissues.
Some of the conditions that rheumatologists treat are rheumatoid arthritis, ankylosing spondylitis, gout, sarcoidosis, vasculitis, and lupus. These are all conditions that involve a lot of pain and make mobility difficult. Rheumatologists use medications, such as analgesics, NSAIDs, steroids, DMARDs, infliximab, and adalimumab, as well as occupational therapy, in order to decrease pain and improve a patient's quality of life.

An internist is a physician who focuses on the diagnosis and treatment of conditions that affect the adult population—both acute and chronic.
These doctors are often who adults see as their primary physicians because they treat a broad range of illnesses that do not require surgical or specialist interventions. They also work to help a patient maintain optimal health in order to prevent the onset of disease.
In addition to treating the common cold and flu, internists also treat chronic diseases like diabetes and heart disease.