Upadhyaya was born in India. She entered an arranged marriage when she was 18 years old and joined her husband, an engineer, to the United Kingdom a year later. Having studied an honours bachelor's degree in biology at the University of Delhi, she completed a Master of Science at the University of Edinburgh followed by a doctorate at Cardiff University. Upadhyaya completed a fellowship with the Royal College of Pathologists in 2000, becoming one of the first people to do so in the field of medical genetics. Her research career focused on genetic disorders, especially neurofibromatosis type I and facioscapulohumeral muscular dystrophy. She was involved in identifying the genetic mutations responsible for these two diseases and to evaluate whether certain mutation was associated with specific clinical features. She developed molecular tests to aid in the diagnosis of more than 20 genetic diseases including neurofibromatosis type 1. She has also researched the reasons that in some people with neurofibromatosis type I, the benign tumours can become malignant. Using high-throughput techniques, she was able to identify molecular targets which will be important for the treatment of the patients. Over her career, she authored more than 200 scientific articles and three textbooks and received awards from the Muscular Dystrophy Association, the Inspire Wales Awards, the European Neurofibromatosis Group, and the Welsh Assembly. She was a professor in Cardiff University's Institute of Cancer Genetics and directed the All Wales Medical Genetics Service Research and Development Laboratory until her retirement in 2014, thereafter serving as an honorary distinguished professor at Cardiff. She received an OBE in 2016 for "services to medical genetics and the Welsh Asian community". She received St David Award in 2017 in Innovation, Science and Technology category for her outstanding contribution to medical genetics. Upadhyaya became UK's first female British-Indian professor to receive Honorary Fellowship at University of Wales Trinity Saint David in 2017. She is listed as one of the 100 Wales's brilliant women by WalesOnline. She also made to the list of 100 Welsh Women, created by Women's Equality Network, to mark the centenary of the Representation of the People Act 1918. She was awarded the prestigious fellowship of Learned Society of Wales in 2018. She has been an International Advisor for the Organisation of the Rare Diseases, India and also sits on the Advisory Board of genoma India international forum, Philadelphia, USA and on the Medical Advisory Board of Neuro Foundation, UK. Upadhyaya is a co-director of the project entitled: 70 years of struggle and achievement: Life Stories of Ethnic Minority Women in Wales 2019. She organised First International Conference on RASopathies and Neurofibromatoses in Asia: Identification and Advances of New Therapeutics in Kochi, Kerala, India in 2017. She was elected to be a Council Member of the RCPath in 2014 and the Learning Society of Wales in 2020. Upadhyaya also served as a mentor on Dame Rosemary Butler's Women in Public Life Scheme. She is a trustee for Race Equality First, Race Council Cymru, the European NF Association and sits on the Advisory Committee of Cardiff University's BME+ Staff Network, NWAMI, Purple Plaque, and Monumental Welsh Women. Upadhyaya has been appointed as a Non-Executive Director on the Welsh Government Civil Service Board. Upadhyaya is also an advocate for women of ethnic minorities; she founded the Welsh Asian Women Achievement Awards, now and the organisation . She sits on many committees focusing on equality, diversity and academia.
