Dr. Wangnoo completed his Graduated and Post graduated from Institute of Medical Science, BHU, Varanasi. He started his career as Registrar    at BHU, Varanasi in October 1981 and joined as Lecturer (Endocrinology), SKIMS, Srinagar in July 1984. He left SKIMS, Srinagar as Associate Professor and HOD (Endocrinology) in March 1990. Dr. Wangnoo worked as Sr. Consultant (Endocrinology) at NMH, Mohan Nagar, Ghaziabad from 1990 to 1992 and at KKH, Hail, Saudi Arabia from 1992 to Dec 1994 . In November 1995 he joined Apollo Hospital, New Delhi as Sr. Consultant (Endocrinology).

Dr. Wangnoo is a professional member of Endocrine Society of India (ESI), American Diabetic Association (ADA), International Diabetes Federation (IDF) & EASD; Indian Menopause Society (IMS), Delhi Diabetic forum (DDF), Research Society for study of diabetes in India (RSSDI) and ISBMR

He is an invited faculty for major Orations, National and International conferences and was a WHO fellow in 1988. Dr. Wangnoo is President of Delhi Diabetic forum and Panel member for IDC – WHO global consensus guidelines for SMBG. He is also an external examiner for DM & faculty for DNB (Endo) training programme.