Endocrinology is perhaps, the only branch of medicine where stimulation and suppression testing are required as the initial step for biochemical confirmation of the clinical condition as hormone secretion is pulsatile. One of the primary needs for an endocrinologist is a pocketbook that can serve as a guide for performing and interpreting these tests. Unfortunately, there is no single source of these protocols, procedures, and interpretation of these tests in the country or even in the Southeast Asia region. This protocol manual is designed to be a ready reckoner for endocrinologists for performing these tests. 

Disorders of various endocrine glands, including pituitary, thyroid, pancreas, adrenal, gonads, and bone and mineral disorders, have been addressed. The book includes prerequisites and indications of a given test, principles of the testing, detailed procedure, and interpretation. Participant information and instruction sheets have been included, when applicable, to be given as a handout to patients prior to these tests. The manual contains algorithms (e.g., for approaching cases with hypoglycemia) and interpretation provided in a tabular format. It also lists troubleshooting measures for specific tests, when applicable. Further, clinical case scenarios substantiated by clinical and radiological images have been incorporated in the manual to highlight the procedure and interpretation of these tests in the management of challenging clinical cases. The manual is designed to be a comprehensive yet concise document covering all these aspects. Besides blood-based investigations, procedures which are undertaken in challenging endocrine scenarios, including inferior petrosal sinus sampling, and adrenal venous sampling have been elucidated in a crisp and practical manner. 

Dr. Sanjay Kumar Bhadada is currently working as professor and head of the Department of Endocrinology at the Postgraduate Institute of Medical Education and Research (PGIMER), Chandigarh. He has more than 250 peer-reviewed international publications and has delivered numerous oral and posters presentations in multiple international meetings. He is the President-Elect of the Endocrine Society of India and RSSDI (Punjab Chapter). He is on the editorial board of reputed journals such as the Journal of Clinical Endocrinology and Metabolism, Calcified Tissue International, and Journal of Endocrine Investigation. He is also the principal investigator of the Indian PHPT Registry and the rare metabolic bone disease registry. 

Dr. Liza Das is a clinical endocrinologist working at the department of Endocrinology, Postgraduate Institute of Medical Education and Research (PGIMER), Chandigarh. She has, to her credit, over 60 peer-reviewed publications in acclaimed journals like Diabetes Care, Frontiers in Endocrinology, Pituitary and Journal of Endocrinological Investigation. Her work also includes book chapters in national textbooks about diabetes, pituitary, and COVID-19. She also serves on the editorial board of prestigious journals such as Frontiers in Endocrinology and Plos One and is a reviewer for international journals. Apart from presentations at the US Endo, British Endocrine Society and the international webinar in pituitary medicine (Endotext), she was recently invited for her guest lecture at US Endo, 2022 in the Pituitary symposium.

Dr. Rimesh Pal is presently working as an Assistant Professor in the Department of Endocrinology at the prestigious Postgraduate Institute of Medical Education and Research (PGIMER) Chandigarh, India. He has more than 100 peer-reviewed publications in renowned international and national journals, including The Lancet Diabetes& Endocrinology, Nature Reviews Endocrinology, Diabetes Research and Clinical Practice, Osteoporosis International, Frontiers in Endocrinology, Journal of Endocrinological Investigation, Indian Journal of Medical Research, amongst others. He is a regular reviewer for multiple international and national journals. Besides, he is an Editor of multiple international journals, notably, the Therapeutic Advances in Endocrinology and Metabolism, Journal of Osteoporosis, Endocrine and Metabolic Science, Frontiers Endocrinology: Bone Research, and PLOS One. He was the recipient of the distinguished C. Wayne Bardin International Travel Award for the year 2022 which is awarded by the Endocrine Society to only one endocrinologist globally.

Protocol for testing in diabetes, thyroid and related disorders.- Standard oral glucose tolerance test.- Evaluation of gestational diabetes mellitus.- Glucagon-stimulated c-peptide test.- Mixed meal test.- Prolonged supervised fast.- Selective arterial calcium stimulation test.- TRH releasing test.- T3 suppression test.- Protocol for testing in pituitary disorders.- Insulin induced hypoglycaemia/Insulin tolerance test.- Clonidine stimulation test.- Glucagon stimulation test.- Levodopa stimulation test.- Oral glucose tolerance test for acromegaly.- Bilateral inferior petrosal sinus sampling.- CRH stimulation test.- AVP stimulation test.- Low dose dexamethasone suppression test.- High dose dexamethasone suppression test.- Patient instruction sheet for dexamethasone suppression test.- Patient instruction sheet for 24 hour urinary free cortisol estimation.- Patient instruction sheet for 2300 h awake cortisol.