Armpits only smell when I go outside?

Name: 
Ana
More information: 
I don't sweat much. However, if I go outside when it is mildly hot out, my armpits smell terrible. On the contrary, if I'm at the gym and sweating buckets, there is no smell. Also, if I'd go outside and run (sweat) in winter, no smell. Please help as I've tried so much for this.

Comments

Hi Ana, thanks for your question. This nicely shows the impact of the sweat glands. You have two kinds of sweat glands in the armpit: eccrine sweat glands, which mainly produce water and salts; and apocrine sweat glands, which produce a lipid-rich solution to lubricate the friction in the underarm region. If you run outside or at the gym, sweating buckets, the eccrine sweat glands will be very active, mainly producing water and salts in the process. If it is mildly hot, or when in the office, or under stress, the apocrine sweat glands will be more active, secreting lipids, hormones, precursors of odor. Bacteria are living on the skin and inside the sweat glands / hair follicles converting these molecules and can thus result in odor formation.