Skip to content

Sign Up For COVID-19 Text Alerts

express care logo


Our Rheumatologist serves patients in Haverhill, Riverwalk, and Andover

Leading the team, board certified rheumatologist, Dr. William O’Brien diagnoses and treats rheumatic diseases associated with:

  • Inflammatory arthritis  -rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis, gout
  • Vasculitis and connective tissue disorders – lupus, raynauds, sjogrens, antiphospholipid syndrome, scleroderma, giant cell arteritis, Behcet’s, granulomatous polyangiitis, polyarteritis nodosa
  • Muscle and joint disorders – osteoarthritis, polymyalgia rheumatica, bursitis, tendonitis, fibromyalgia, and other causes of musculoskeletal pain

Being mindful of our patients’ time and needs, we provide timely updates to each patient’s referring physicians.  We do this through our onsite lab and diagnostic services as well as the Electronic Health Record that allows the care team to have access to a patient’s real time health information.

Should a patient require more specialized care, we refer to local area hospitals as well as Mass General and Brigham’s & Women’s Hospital in Boston.

With chronic health issues, we strongly believe in patient education and encourage each patient to take an active and responsible role in their healthcare.

Click for additional resources.

To schedule an appointment contact (978) 521-3200. Dr. O’Brien sees patients at our Haverhill and RiverWalk offices.


Pentucket Medical has remained committed to ensuring the safety of our patients during the COVID-19 pandemic.

Since June 1, we have been treating patients on-site per the four-phase guidance issued to healthcare facilities by Governor Baker and the Massachusetts Department of Health and Human Services.

In the coming weeks, we will continue following stringent infection prevention processes and implementing specific precautions to ensure a safe environment for essential patient care services.

Here are some of the changes you will see on your next visit to Pentucket Medical:

When scheduling an appointment with a clinician, you will be provided a phone number to call when you arrive at the office this will allow you to remain safe in your car until it is time to see your provider essentially cutting out waiting rooms

We appreciate your support.


Enroll/Log in Now