Body odor is a fact of life. Some people perspire more than others, and sometimes it can smell undesirable. Sweat can also cause some ugly yellow armpit stains on your favorite shirt. (Actually, sweat is colorless; but the aluminum used in antiperspirants can chemically react with your sweat, causing the stains.)
It’s normal to sweat, and for some, sweating is a natural response to stressful situations. However, unusual changes in your perspiration may be a red flag for something more serious. Excessive sweating often known as hyperhidrosis or little to no perspiration known as anhidrosis, can be cause for concern and a good reason to consult your primary care physician.
– Charles Falzon, MD, primary care physician, Northwestern Medical Group