I always get bumps or lumps under armpits when I shave. Sometimes they are painful and sometimes they arent. Wht cld it be?

It can be hair folli. This could be irritation of the hair follicles. There are certain medical conditions that can lead to this. Your physician may send you to a dermatologist to clarify the diagnosis. This can be a common problem when hair follicles are irritated. However there are some medical syndromes which can irritate a lot of hair follicles and that needs to be excluded. These hair follicles can be infected.