1 00:00:02,040 --> 00:00:08,039 Speaker 1: Welcome to brain stuff from how stuff works. Everyone, I'm Christian, 2 00:00:08,440 --> 00:00:11,959 Speaker 1: and you you stink? I mean, don't take it personally. 3 00:00:11,960 --> 00:00:15,200 Speaker 1: Pretty much everyone stinks, and pretty much everybody sweats too. 4 00:00:15,440 --> 00:00:19,079 Speaker 1: There's nothing inherently wrong with these natural body processes. But 5 00:00:19,440 --> 00:00:21,799 Speaker 1: in modern society we don't want to be at the 6 00:00:21,800 --> 00:00:25,360 Speaker 1: whim of evolution. Who wants to spend all summer covered 7 00:00:25,400 --> 00:00:27,680 Speaker 1: in sweat stains or show up at a job interview 8 00:00:27,720 --> 00:00:30,720 Speaker 1: looking like you ran two miles to get there. Sweat 9 00:00:30,840 --> 00:00:34,120 Speaker 1: can affect the way other people view you. A study 10 00:00:34,200 --> 00:00:39,400 Speaker 1: conducted by the International hyper Hydrosis Society explored the social 11 00:00:39,440 --> 00:00:43,600 Speaker 1: stigma of sweat, with sixty six percent of respondents claiming 12 00:00:43,640 --> 00:00:46,879 Speaker 1: that visible sweat made them think a person was nervous, 13 00:00:47,120 --> 00:00:52,559 Speaker 1: while believed those showing excessive sweat to be overweight. If 14 00:00:52,560 --> 00:00:55,840 Speaker 1: you want to avoid excessive sweating, or if you're a 15 00:00:55,960 --> 00:01:00,480 Speaker 1: naturally heavy sweater, then you probably need an antiperspirant. Pretty 16 00:01:00,480 --> 00:01:03,120 Speaker 1: amazing stuff. You just take a quick roll and boom, 17 00:01:03,120 --> 00:01:06,039 Speaker 1: your sweat problem is salved. But what is this stuff 18 00:01:06,040 --> 00:01:08,800 Speaker 1: and how does it actually work? Well? First, we have 19 00:01:08,920 --> 00:01:14,120 Speaker 1: to make a distinction between deodorant and antiperspirant. Deodorant targets 20 00:01:14,120 --> 00:01:18,160 Speaker 1: bacteria under your armpits, making the skin they're too salty 21 00:01:18,319 --> 00:01:22,319 Speaker 1: or acidic to support bacteria responsible for your body odor. 22 00:01:22,760 --> 00:01:26,440 Speaker 1: Antiperspirants can cut down on body odor two, but they're 23 00:01:26,440 --> 00:01:30,039 Speaker 1: primarily made to keep you from sweating. You have two 24 00:01:30,120 --> 00:01:33,440 Speaker 1: types of sweat glands all over your skin, and they're 25 00:01:33,520 --> 00:01:37,319 Speaker 1: most concentrated in your under arms. The ecrine glands are 26 00:01:37,360 --> 00:01:40,280 Speaker 1: the most numerous. They kick in to cool you off 27 00:01:40,400 --> 00:01:44,759 Speaker 1: when you're hot. So when you're exposed to heat, physical exertion, stress, 28 00:01:44,920 --> 00:01:49,840 Speaker 1: or nervousness, these sweat glands are stimulated. The cells secrete 29 00:01:49,880 --> 00:01:52,760 Speaker 1: a fluid that travels from the coiled portion of the 30 00:01:52,800 --> 00:01:56,360 Speaker 1: gland up through the straight duct and out onto the 31 00:01:56,400 --> 00:02:01,680 Speaker 1: surface of our skin. These ecrine glands excrete, water, and salt, 32 00:02:02,040 --> 00:02:04,920 Speaker 1: and for the record, have nothing to do with your 33 00:02:04,920 --> 00:02:08,080 Speaker 1: body odor. The ap acrine glands, on the other hand, 34 00:02:08,320 --> 00:02:12,920 Speaker 1: those carry secretions of fats and proteins along with your sweat. 35 00:02:13,320 --> 00:02:16,880 Speaker 1: Once this hits the exterior surface of your skin, those 36 00:02:16,919 --> 00:02:22,480 Speaker 1: fats and proteins react with bacteria to create odors. Antiperspirants 37 00:02:22,560 --> 00:02:26,320 Speaker 1: have an active ingredient that gives them sweat blocking power. 38 00:02:26,400 --> 00:02:30,440 Speaker 1: Typically it's an aluminium based compound like aluminium chloride or 39 00:02:30,480 --> 00:02:35,240 Speaker 1: aluminium chlorohydrate. When this ingredient gets into the duct leading 40 00:02:35,280 --> 00:02:39,400 Speaker 1: to each sweat gland, the aluminium ions enter the cells 41 00:02:39,520 --> 00:02:43,960 Speaker 1: lining the ecrene gland ducts. As the ions enter, water 42 00:02:44,040 --> 00:02:47,959 Speaker 1: passes into the cells with them. As more water enters, 43 00:02:48,240 --> 00:02:52,440 Speaker 1: the cells around the duct begin to swell. These cells 44 00:02:52,520 --> 00:02:57,239 Speaker 1: can swell enough to squeeze the ducts closed. At that point, 45 00:02:57,520 --> 00:03:00,560 Speaker 1: sweat can't get out, and you're staying free for a while. 46 00:03:01,080 --> 00:03:04,240 Speaker 1: Each cell can only draw in a certain amount of water, 47 00:03:04,400 --> 00:03:08,960 Speaker 1: so eventually the concentrations of water outside and inside the 48 00:03:09,000 --> 00:03:13,560 Speaker 1: cells reach equilibrium. When this happens, the water inside the 49 00:03:13,560 --> 00:03:17,919 Speaker 1: cell begins to pass back out of the cell through osmosis, 50 00:03:18,000 --> 00:03:22,200 Speaker 1: and the cells swelling goes down. This is why people 51 00:03:22,240 --> 00:03:27,200 Speaker 1: have to reapply antiperspirant. An average over the counter antiperspirant 52 00:03:27,400 --> 00:03:31,960 Speaker 1: might have an active ingredient concentration of fifteen. If you've 53 00:03:32,000 --> 00:03:35,480 Speaker 1: got a real sweating problem, doctors can prescribe much stronger 54 00:03:35,480 --> 00:03:38,240 Speaker 1: products for you, but will you want to take them? 55 00:03:38,280 --> 00:03:42,520 Speaker 1: You see, antiperspirance aren't perfect. Some studies have claimed a 56 00:03:42,600 --> 00:03:46,840 Speaker 1: link between breast cancer and antiperspirance, although for now that 57 00:03:46,960 --> 00:03:51,760 Speaker 1: link remains inconclusive. There's another concern to people without fully 58 00:03:51,760 --> 00:03:56,560 Speaker 1: functioning kidneys should be wary of using antiperspirant. In the US, 59 00:03:56,680 --> 00:04:00,200 Speaker 1: the Food and Drug Administration requires a warning label on 60 00:04:00,320 --> 00:04:04,200 Speaker 1: all antiperspirants, stating that people with kidney disease should consult 61 00:04:04,320 --> 00:04:08,400 Speaker 1: a doctor before using them. If you're not comfortable using antiperspirant, 62 00:04:08,440 --> 00:04:12,920 Speaker 1: then hey, no worries, Just go for an aluminum free deodorant. 63 00:04:13,160 --> 00:04:15,720 Speaker 1: It won't stop the sweat, but it will knock out 64 00:04:16,040 --> 00:04:24,200 Speaker 1: that odor. Check out the brainstuff channel on YouTube, and 65 00:04:24,240 --> 00:04:26,680 Speaker 1: for more on this and thousands of other topics, visit 66 00:04:26,720 --> 00:04:41,080 Speaker 1: how stuff works dot com.