By Martha A. Simpson, D.O., M.B.A.
Associate Professor of Family Medicine
Ohio University College of Osteopathic Medicine

MORE SWEAT DURING HOT WEATHER DOESN’T REQUIRE MORE DEODORANT

Question: In the summer months, I always use a lot more deodorant because I sweat so much more in hot weather. A friend of mine recently told me that it wasn’t necessary to use more deodorant in the summer -- that it would just clog my pores and make things worse. Does she know what’s she’s talking about?

Answer: In the summer months, those of us who live in the temperate climate of North America have a tendency to pile on the deodorant. The reason is that during these hot, muggy and sweaty afternoons and evenings we think that the additional sweat we produce means an increase in body odor. So, almost instinctively, we use more deodorant to keep from alienating our friends and co-workers with offensive odors.

However, this is a case where our instincts are wrong. It is, in fact, really not necessary to use more deodorant at this time of year. This is because "hot weather sweating" has virtually no effect on body odor. The reason is that the increased sweat produced by a summer "heat wave" is actually the wrong kind of sweat.

Confused? Let me explain. The human body produces two distinctly different kinds of sweat. One comes from eccrine glands located throughout the body and is produced by heat stimulation and by emotional factors. It's ninety-nine percent water and has almost no smell at all. The other kind of sweat comes from the apocrine glands that are located primarily in the underarm area -- but are also found about the ears, nipples, navel and genital region. They are stimulated solely by your emotions -- especially stress and sexual stimulation and produce a thicker, slightly milky liquid.

Apocrine sweat does smell. This is because it's composed of complex organic molecules that are quickly decomposed by the bacteria on the skin. Further, the underarm environment is ideally suited for the growth of this bacteria. It's warm and supplied with additional moisture from eccrine sweat glands that are also located there.

Since eccrine sweating does increase in hot weather, more frequent applications of antiperspirant in the underarm area may be desirable. But, you don't really need additional deodorant unless you are under increased emotional stress.

In terms of the question of clogging pores, it’s generally not an issue. Most commercial deodorant and antiperspirant products are formulated so that they don’t clog pores.

One final word about the natural process of sweating. While it may be helpful to control underarm sweating for aesthetic reasons, you should not conclude that sweat is somehow a completely negative thing. Quite the contrary -- sweat is a necessary part of everyday life. The three million eccrine sweat glands are part of the body's temperature regulating system. When overheated, your body sweats so that the evaporation of this liquid from the skin surface can reduce skin temperature. This, in turn, helps to cool the blood that circulates close to the surface, and your circulation then returns this cooler blood to internal body organs. Without this simple cooling mechanism, a slight change in environmental temperature would cause death.

Family Medicine® is a weekly column. To submit questions, write to Martha A. Simpson, D.O., M.B.A., Ohio University College of Osteopathic Medicine, P.O. Box 110, Athens, Ohio 45701, or via e-mail to readerquestions@familymedicinenews.org. Medical information in this column is provided as an educational service only. It does not replace the judgment of your personal physician, who should be relied on to diagnose and recommend treatment for any medical conditions. Past columns are available online at www.familymedicinenews.org.