More than 2.5 crore people in the world could be living with Parkinson's disease by 2050, largely driven by an ageing population, according to a study. Researchers, including those from the Capital Medical University, China, said the projected numbers are a 112 per cent increase from cases in 2021. Further, cases of the neurological disorder from South Asia are predicted to be the second highest at 68 lakh, following East Asia (over 1 crore), the findings, published in The British Medical Journal, suggested. The researchers said the estimates could "serve as an aid in promoting health research, informing policy decisions and allocating resources". Parkinson's disease is a neurodegenerative disorder in which one's movements and balance are steadily affected. The condition can also cause problems with speech, memory and behaviour. Symptoms include tremors in parts of the body and muscle stiffness. The researchers analysed data from the Global Burden of Disease Study 2021 to estimate