Inequities and gaps in palliative care access are a serious impediment to health systems especially low- and middle-income countries and the accurate measurement of need across health conditions is a critical step to understanding and addressing the issue. Serious Health-related Suffering (SHS) is a novel methodology to measure the palliative care need and was originally developed by The Lancet Commission on Global Access to Palliative Care and Pain Relief. In 2015, the first iteration - SHS 1.0 - was estimated at over 61 million people worldwide experiencing at least 6 billion days of SHS annually as a result of life-limiting and life-threatening conditions. In this paper, we present an updated methodology - SHS2.0 - building on the work of the Lancet Commission and detailing calculations, data requirements, limitations, and assumptions. Our updates to the original methodology focus on measuring the number of people who die with (decedents) or live with (non-decedents) SHS in a given year to assess the number of people in need of palliative care across health conditions and populations. We also share detail on the methodology for measuring the number of days of SHS that was pioneered by the Lancet Commission, as this second measure is essential for determining the health system responses that are necessary to address palliative care need and must be a priority for future methodological work on SHS. We discuss the opportunities for applying SHS to future policy making, assess future research priorities particularly in light of the dearth of data from low- and middle-income countries, and share directions for future work to develop SHS 3.0.