Dr Jonathan Katz

Dr Jonathan Katz

Consultant Endocrinologist


Specialises in

Also available for:

Virtual consultations:

I studied Medicine at Cambridge University (1985-1988) and University College London (1988-1991). I began training in Endocrinology in 1994 at St Bartholomew’s Hospital.  I returned to University College London (UCL) for specialist registrar training from 1994-2001, working at UCL, The Royal Free and Whittington Hospitals.

From 1996-1998, I undertook a 2-year research fellowship, culminating in an MD Thesis on “obesity and polycystic ovary syndrome”. In 1999, I worked as a registrar in Sydney, Australia. I began my career as a Consultant Endocrinologist in the UK in 2001.

I work as a Consultant Endocrinologist for the Royal Free London NHS Foundation Trust, based at Barnet Hospital.  In 2009, I was elected as a Fellow of the Royal College of Physicians (FRCP), an honour granted to consultants providing the highest standards of care.  In 2019, I was appointed as Regional Advisor for the Royal College of Physicians – this is an elected post with wider responsibilities supporting training, ensuring new consultant posts fulfil Royal College standards, appointing College Tutors and vetting FRCP applications

I have a busy NHS Endocrinology practice, seeing over 300 new patients and over 1000 follow-up patients each year. In addition, I look after inpatients at Barnet Hospital with diabetes emergencies and acute endocrine disorders. I have over 20 years’ experience in diagnosing and treating the full range of endocrine disorders. Whether you have a newly diagnosed problem or are seeking a review of your treatment, I am well placed to advise and help.


Treatment information

Some of the principal treatments carried out by Dr Jonathan Katz at Spire include:

Other treatments

  • Adrenal disorders
  • Diabetes
  • Menopause
  • Polycystic ovary syndrome
  • Prolactinomas and other pituitary disorders
  • Testosterone deficiency
  • Thyroid disorders - overactive & underactive thyroid;  thyroid nodules / goitre

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Important information about COVID-19 tests

COVID-19 testing or antibody tests are not available as a standalone service at Spire Bushey Hospital.


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Additional information


Thyrotoxicosis, Hypothyroidism and Reproductive Endocrinology

Professional memberships

Fellow of Royal College of Physicians

Diabetes UK

Society of Endocrinology

Consultant in Diabetes & Endocrinology for the Royal Free London NHS Foundation Trust, based at Barnet Hospital, where I look after both inpatients and outpatients with diabetes, thyroid disease and other hormone imbalances.

I enjoy family life, photography and travel.  As well as recommending exercise, I like to keep fit, especially swimming and cycling. When possible, I try and fit in a week of skiing!