Want to schedule an appointment?
Call us on (757)484-9400

About Us

A few words about us

We have been Serving community since 1980. Portsmouth Nephrology is pleased to provide complete, personalized renal care to Our community.

Portsmouth Nephrology physicians are Certified by the American Board of Internal Medicine—Subspecialty of Nephrology. We provide consultative and ongoing care for patients with a myriad of kidney-related conditions such as Chronic Kidney Disease, Hypertension, Acute Kidney Injury, Hematuria, Proteinuria , Kidney stones, inherited Cystic Kidney Disease, such as polycystic kidney disease, glomerulonephritis.

In addition to our interest in various aspect of dialysis including Hemodialysis and Peritoneal Dialysis therapy for the majority of our patients with End Stage Renal Disease (ESRD).

Information for Patient

We provide care for following conditions

Acute Kidney Injury

Chronic kidney disease


Cystic Kidney Disease

Kidney Stones


Electrolyte Abnormalities


Kidney Transplant

End Stage Renal Disease

Our Providers

Meet our doctors

Dr. Keith Zaitoun

  • He finished medical training in 1991 and joined Portsmouth Nephrology in 1993.
  • Medical schoolUniversity of VA Medical School
  • ResidencyEastern Virginia Medical School
  • FellowshipMedical College of Virginia (VCU)
  • Board CertificationsInternal Medicine, Nephrology
  • Special InterestsAcute Kidney Injury, Transplant, electrolyte problems, dialysis
  • LanguagesEnglish, Lebanese, Arabic, French

Dr. Antonietta M. Castanares

  • She finished her medical training in 1995 and joined Portsmouth Nephrology in 1998.
  • Medical SchoolCebu Institute of Medicine
  • ResidencyLong Island College Hospital
  • FellowshipLong Island College Hospital ,Brooklyn, NY
  • Board CertificationInternal Medicine, Nephrology
  • Special interestsCKD, Hypertension, Home Dialysis.
  • LanguagesEnglish, Tagalog

Dr. Krunal Patel

  • Dr. Patel joined Portsmouth Nephrology in 2013.
  • Medical SchoolPDU Medical College , Rajkot, India
  • ResidencyMount Sinai Medical Center, Elmhurst.
  • FellowshipNephrology Fellowship at Mount Sanai Medical Center, Elmhurst. Critical Care Fellowship at Mount Sinai Medical Center, New York
  • Special InterestsAcute Kidney injury, Hypertension, Kidney Stone, ICU Nephrology
  • LanguageEnglish, Hindi, Gujarati

Lavon O’Toole

  • Practice Manager

She is native of Hamton Roads and graduate of Indian River High School. She attended Old Dominion University and ECPI college of Technology.

Lavon has 25+ years of medical billing and management with over a decade in Nephrology. She Joined Portsmouth Nephrology in 2015.

Dr. Ali Choudhury, MD

Retired physician of Portsmouth nephrology.

Dr. Martin Harpen

Retired physician of Portsmouth nephrology.


Most common reason for patient to be referred by primary care to a nephrologist (Physician who specialize in kidney disease) is because of abnormal kidney function result in laboratory report. It is possible and quite common that Patient may not have any specific symptoms.

Other common conditions are blood or protein in urine, kidney stones and cystic kidney disease.

Your Primary Care Physician seeks the guidance from nephrologist colleague to determine the root cause or causes and collaborate to provide the best possible plan of treatment.

It is not uncommon that patient may not feel any obvious symptoms. Severe symptoms of renal failure such as short of breath, itching, weight loss, poor appetite, leg swelling etc usually seen in very late stage of renal disease.

However, once kidney function declines to the point of needing significant intervention, patients won’t “feel well” anymore, inevitably experiencing symptoms and needing further intervention or treatment. Our goal as Nephrologist is to keep you “feeling well” and keep those kidneys functioning as well as possible, for as long as possible.

You should not need dialysis until your kidney function is less than 15%. At that point you will begin to feel unwell and treatments/interventions are no longer effective in managing symptoms and supplementing the functions of your kidneys. This can be a very slow transition for some patients. In general, many patients do not have any obvious symptoms of kidney disease until the kidneys actually begin failing.

  • Maintain tight control on your blood pressure. Typically this is less than 140/80 but your doctor may have different guidelines based on your specific health condition.
  • Maintaining a low sodium diet will assist in this process (less than 2000mg/day).
  • Maintain tight control over your blood sugar if you are a diabetic.
  • Stay well hydrated.
  • Let your physician know if you become ill, especially with vomiting/diarrhea.
  • Notify your physician if you are prescribed new medications to ensure they are ok and the dosing is appropriate for your level of kidney function.
  • What caused my kidney disease ?
  • What is creatinine and GFR and what is mine?
  • Do I have hypertension, diabetes, at goal to avoid further decline in my kidney function?
  • If I have an acute kidney problem, do you expect me to recover, and how long might that take?
  • If my kidney problem is chronic, how long can I continue without dialysis, or will I ever need dialysis?
  • Am I a good candidate for a kidney transplant?
  • What dietary and life style changes do I need to make during treatment or recovery?


Main Address
3235 Academy Ave # 301, Portsmouth, VA 23703

Contact Us

© 2017 Portsmouth Nephrology. All rights reserved