Why hot spring good for skin troble?

Last year I went japan and I enjoyed hot spring. I have some skin problem. After enjoying hot spring, my skin has no problem. What make my skin clear ?

Some hot springs contain baking soda (Sodium Hydrogen Carbonate). It makes skin smoother. Sometimes those hot springs are called "bijin no yu", literal meaning is "hot spring of beauty".

Hot springs contain various minerals that are supposed to be good for your health.

Each bath has an official (Japanese) sign on the wall mentioning what it is supposed to be good for, and many of them are supposed to be good for skin problems. As it is so in many countries, hot springs resorts have worked as places to heal your health problems.

Hot springs not only affect the surface of your body, but works on your inner side such as your organs. Therefore, those with heart deseases or those who are pregnant are often restricted from the bath (it is mentioned on the official sign). You may also notice that you tend to stay warmer after a hot spring bath compared to how you'd feel after an ordinary bath.

Skin problems not only occur due to reasons affecting the surface of your skin, but also from your organs or invisible reasons like mental stress. It makes sense that hot spring resorts can cure those reasons.

Some hot springs sell bath powder in which you can pour into your home tub in hope for similar effects. You might want to check the accomodation or tourist information center of the place you stayed.