"The global population is rising, but the number of health workers is stagnating or even falling. This is especially true in places with the most serious health problems," the WHO’s Western Pacific Region Office said on its website.
WHO will devote the 56th World Health Day celebration on April 7 to the crisis. On that day, hundreds of organizations around the world will host events intended to draw attention to the problem and to celebrate the "dignity and value of working for health."
WHO estimates the present global health workforce to be around 59 million men and women, with 39.5 million health service providers and over 19.5 million management and support workers.
However, the international agency said there is a global shortage of more than four million doctors, midwives, nurses, pharmacists, dentists and support workers.
"The global population is rising, but the number of health workers is stagnating or even falling. This is especially true in places with the most serious health problems. Across the developing world, health workers are facing economic hardship, deteriorating health infrastructures and social unrest," WHO added.
In developed countries, WHO said there has been an "ever-growing" demand for health workers and this is answered by recruiting trained workers from the developing nations.
WHO cautioned that this strategy increases the shortage of skilled human resources in the poorest countries.
"Decades of cost-cutting and under-investment in health have also resulted in truly terrible working conditions for many in the health workforce," the agency said.
"The morale and performance of overburdened, underpaid and unsupported health workers have sharply declined. As a result, many health workers feel they can no longer continue under these conditions," WHO added.
Experts have warned that the Philippine healthcare system could become critical if the shortage of medical professionals is not addressed within the next few years.