My Qualifications

Professional Degrees/ Certifications/Licenses

  • Master of Nursing Degree, University of Washington 2009
  • Bachelor of Science Nursing, Seattle University 1983
  • Adult Nurse Practitioner Board Certification, American Nurses Credentialing Center
  • Advanced Oncology Nurse Practitioner Certification
  • Advanced Cardiovascular Life Support Provider Certification
  • Advanced Registered Nurse Practitioner, Washington State: AP60097092
  • Registered Nurse, Washington State: RN00085091

Clinical Work Experience

  • Stanford University Medical Center Research Oncology Unit
  • Fred Hutchinson Cancer Research Center
  • Swedish Medical Center
  • Seattle Cancer Care Alliance
  • Overlake Cancer Center
  • Nurse Practitioner in Breast Surgery
  • Breast Cancer Survivorship Program Director

Academic Affiliations and Teaching Experience

  • Affiliate Faculty Member University of Washington School of Nursing, Department of Child, Family and Population Health Nursing
  • National and International Lecturer on Oncology Treatment and Symptom Management

Professional Memberships

  • American Academy of Nurse Practitioners
  • Oncology Nursing Society

About Me

I was born and raised in Seattle; one of five children (one of my four older brothers named me Muff!) From the time I can remember, I was fascinated with all things medical. I particularly loved following my father, an OB/GYN physician on his hospital rounds and learning first hand that a kind and supportive bedside manner was a crucial part of good patient care. After my father passed away from cancer when I was 19, I decided to become an oncology nurse and set out to improve the experience for patients and families dealing with cancer.

I have over 10 years of experience working specifically with breast oncology patients including over 7 years as a Nurse Practitioner in Breast Surgery. I also supported their medical oncology team, by providing chemotherapy education and sharing in the follow up of many of their breast oncology patients.  Recognizing the needs of patients following completion of treatment, I implemented and ran a Breast Cancer Survivorship program designed to address the many questions and issues patients face in the years after their initial treatment has been completed. Helping individuals regain a sense of wellness after cancer treatment is a particular passion of mine.

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Since 2012, I have maintained an affiliate faculty position at the University of Washington School of Nursing in the Department of Child, Family and Population Health Nursing. I have served as a guest lecturer, preceptor and mentor for students and lectured nationally and internationally on a variety of oncology topics, with an emphasis on management of treatment-related symptoms.

I have developed a vast number of patient education materials to assist individuals in understanding and managing the many aspects of their care and recovery from cancer treatment.

It has been an honor and privilege to help thousands of people through their cancer journey. My practice at By Your Side is the opportunity to use all I have learned over my career, to provide highly personalized care for you. It will be my honor and privilege to be a part of your treatment team.

Muff Heffernan was a godsend for me, and my husband, after I was diagnosed with breast cancer last year. Hearing the words “You have invasive lobular cancer” was frightening and I didn’t know where to turn to navigate through all the information and options. Muff went to appointments with us and afterwards, calmly explained everything in non-medical terms. When there were decisions to be made, she simplified them and helped guide us to the right answer. I had confidence in my decisions because of her knowledge and wisdom. Today I am cancer free, but I can’t imagine going through this experience without Muff and her expertise.”

– Sue, Breast Cancer Survivor

When I was diagnosed with breast cancer in October 2019, my husband and I were completely at a loss as to how to proceed, ie. how to reach out to physicians, which area hospital and team was the best fit for our needs, and simply what was the next step after the diagnosis. Muff listened to my story with care and compassion and because of her extensive professional background was able to calmly present us with a list of providers, logistics and next steps to begin the path to treatment. She made phone calls on our behalf and greatly eased the way forward. Muff was an invaluable lifeline in a very unsettling time for us, and my husband and I are extremely grateful.”

– Nora, Breast Cancer Survivor

By Your Side-Unbelievably Helpful! Muff Heffernan was there for me from start to finish! She is able to connect you to all of the right providers and resources. She has a vast knowledge of breast cancer and explains things to you in very understandable terms. She helps you navigate your unexpected diagnosis in a calm and professional way. Her caring and compassionate, empathetic manner is so supportive. I could not have gotten through this without her!”

– Sheryl, Breast Cancer Survivor