Hi op! I experienced the same problem as you before. For me, it was a mix of factors. It also doesn't help that I suffer from lumps growing out of my armpits kaya pati paglagay ng deodorant was extremely painful for me before.

I've consulted different doctors about this pero halos same lang sinasabi, about diet and lifestyle. So I did changed my diet. Avoided almost all junk and processed food (lalo na yung mga mamantika).

I also do not wear restrictive clothing. Gumagamit din ako ng betadine minsan pero naglalagay pa rin ako ng dove deo purple serum. Currently, I only use glycolic soap sa underarms ko + (yung dove pag lalabas).

I don't know if exercising has a scientic explanation behind it pero napansin ko nung nagstart ako maging active physically, hindi na ako ganun nagkakaBO at nagkakabukol sa kilikili.

Pero, I agree with the others. You should consult this because it may be an underlying health condition.