First, Koreans seldom eat meat, so they seldom get enough protein, which leads to the actual lack of nutritional supplements for muscles. Although eating a lot of meat in a short period of time can supplement the muscles that exercise regularly, muscles that rarely get exercise, such as pectoralis major, cannot be supplemented.

Second, Koreans seldom eat salt, but they eat a lot of vinegar and sugar condiments. Don't worry if you don't like to eat too much and your voice is not hoarse. Compared with Koreans, you still eat too much salt, because salt helps to expel phlegm, which will condense on tracheal cilia and corrode them for a long time, so you will be hoarse.

Third, along the coast of South Korea, the water quality will be affected more or less. China's terrain is high in the west and low in the east, so people who really drink water affected by seawater must be near the sea, while South Korea is surrounded by the sea on three sides and has a hoarse voice.

If there is only one of the above, it will not cause hoarseness in a large area, and almost all the dramas are occupied by Koreans, so many Koreans have hoarseness.