1 00:00:02,040 --> 00:00:07,320 Speaker 1: Welcome to brain Stuff from How Stuff Works. Hey, brain Stuff. 2 00:00:07,360 --> 00:00:10,280 Speaker 1: Lauren Boga Bob here with another classic episode for you. 3 00:00:10,840 --> 00:00:13,840 Speaker 1: Former host Christian Sager is explaining what's too many folks 4 00:00:13,920 --> 00:00:17,200 Speaker 1: a pressing consideration as they get older. Why do some 5 00:00:17,280 --> 00:00:25,799 Speaker 1: people go bald? Hi? I'm Christian Sager and this is 6 00:00:25,840 --> 00:00:28,480 Speaker 1: brain stuff. Have you ever heard that if your maternal 7 00:00:28,520 --> 00:00:31,960 Speaker 1: grandfather went bald, that you will to? Or what about 8 00:00:32,000 --> 00:00:34,480 Speaker 1: the one we're getting? A scalp massage will send more 9 00:00:34,520 --> 00:00:36,880 Speaker 1: blood to your head and cause your hair to grow back. 10 00:00:37,479 --> 00:00:40,200 Speaker 1: Some people also claim that if you shave your hair, 11 00:00:40,360 --> 00:00:43,760 Speaker 1: it will grow back even fullier than before. Sorry to 12 00:00:43,760 --> 00:00:46,800 Speaker 1: break it to you, but all of these are bogus myths. 13 00:00:47,240 --> 00:00:49,680 Speaker 1: As long as men have been losing their hair, they've 14 00:00:49,720 --> 00:00:52,920 Speaker 1: been trying to figure out what causes baldness and how 15 00:00:52,960 --> 00:00:55,960 Speaker 1: they can cure this sign of aging. In fact, it's 16 00:00:56,160 --> 00:01:00,640 Speaker 1: estimated that forty million Americans are losing their hair, and 17 00:01:00,720 --> 00:01:04,120 Speaker 1: that's men and women, and all of those people are 18 00:01:04,160 --> 00:01:07,720 Speaker 1: spending more than one billion dollars a year on everything 19 00:01:07,760 --> 00:01:11,440 Speaker 1: from hair transplants to two pays and spray on hair. 20 00:01:11,959 --> 00:01:15,520 Speaker 1: Now hair, real hair grows just under the skin on 21 00:01:15,600 --> 00:01:19,000 Speaker 1: our heads from the close to one hundred thousand follicles there. 22 00:01:19,400 --> 00:01:23,440 Speaker 1: This growth happens in three phases, the antigen phase where 23 00:01:23,440 --> 00:01:27,480 Speaker 1: it's growing, the catagen phase in between, and the telligen 24 00:01:27,520 --> 00:01:30,840 Speaker 1: phase where it falls out. And hair falling out is 25 00:01:30,920 --> 00:01:34,920 Speaker 1: totally normal. We should lose fifty to one hundred hairs 26 00:01:34,959 --> 00:01:39,080 Speaker 1: every day as part of the intelligence cycle. But if 27 00:01:39,200 --> 00:01:43,200 Speaker 1: more hair falls out then is replaced, you are probably balding. 28 00:01:43,640 --> 00:01:45,920 Speaker 1: If the hair that grows back is thinner than what 29 00:01:46,040 --> 00:01:49,600 Speaker 1: fell out, you're probably balding. And if it starts falling 30 00:01:49,600 --> 00:01:53,680 Speaker 1: out in clumps, oh yeah, you are balding. But hey, 31 00:01:53,960 --> 00:01:56,920 Speaker 1: take comfort that you are not alone. My friends, by 32 00:01:57,000 --> 00:02:00,360 Speaker 1: age thirty, a quarter of all men have already started 33 00:02:00,400 --> 00:02:03,680 Speaker 1: to lose their hair. What's weird is why do humans 34 00:02:03,720 --> 00:02:07,200 Speaker 1: go bald in the first place. Baldness is actually pretty 35 00:02:07,320 --> 00:02:10,080 Speaker 1: rare in other animals, and hair serves a lot of 36 00:02:10,120 --> 00:02:14,280 Speaker 1: important purposes. It protects our heads from the sun, maintains 37 00:02:14,280 --> 00:02:17,760 Speaker 1: our body heat when we're cold, and may even attract mate. 38 00:02:18,240 --> 00:02:21,520 Speaker 1: Some researchers think it suggests a dominant status or a 39 00:02:21,600 --> 00:02:25,720 Speaker 1: sign of maturity in different societies. In fact, a paper 40 00:02:25,760 --> 00:02:30,560 Speaker 1: from the journal Social Psychological and Personality Science found evidence 41 00:02:30,840 --> 00:02:35,160 Speaker 1: that women find completely bald men more attractive than partially 42 00:02:35,160 --> 00:02:38,720 Speaker 1: bald ones. The study also found that baldness was highly 43 00:02:38,760 --> 00:02:43,480 Speaker 1: associated with two traits, dominance and strength. So if you're 44 00:02:43,520 --> 00:02:46,640 Speaker 1: starting to lose your hair, maybe you should take action, 45 00:02:46,919 --> 00:02:49,520 Speaker 1: shave it all off and show the world what a tough, 46 00:02:49,760 --> 00:02:53,960 Speaker 1: assertive man you are. To understand baldness a little better, 47 00:02:54,320 --> 00:02:57,640 Speaker 1: let's look at the different types that occur. First. The 48 00:02:57,680 --> 00:03:02,440 Speaker 1: most common type is called and dro genetic alopecia, otherwise 49 00:03:02,520 --> 00:03:06,279 Speaker 1: known as male pattern baldness. It's related to our inherited 50 00:03:06,320 --> 00:03:10,959 Speaker 1: genetic predisposition from both of our parents. This affects how 51 00:03:11,000 --> 00:03:15,320 Speaker 1: sensitive we are to a hormone called die hydro testosserone, 52 00:03:15,639 --> 00:03:20,919 Speaker 1: hereafter referred to as d HT. For most guys, five 53 00:03:20,960 --> 00:03:24,440 Speaker 1: percent of their testosterone is converted into d h T. 54 00:03:25,160 --> 00:03:27,840 Speaker 1: If you're sensitive to d h T, it acts like 55 00:03:27,880 --> 00:03:32,400 Speaker 1: a toxin on your hair follicles, producing thinner, weaker, almost 56 00:03:32,480 --> 00:03:37,200 Speaker 1: colorless hair until hair production in the follicle simply stops. 57 00:03:38,000 --> 00:03:41,720 Speaker 1: Researchers have also found that male pattern baldness also causes 58 00:03:41,800 --> 00:03:44,920 Speaker 1: men to have an abnormal amount of a protein lipid 59 00:03:45,040 --> 00:03:51,000 Speaker 1: called prostaglandin D two Some dermatologists even think that men 60 00:03:51,440 --> 00:03:55,320 Speaker 1: could regrow their hair if this inhibiting protein were removed. 61 00:03:55,880 --> 00:03:59,080 Speaker 1: Other types of baldness include the female pattern baldness that 62 00:03:59,120 --> 00:04:03,520 Speaker 1: occurs in some women post menopause, an autoimmune disorder called 63 00:04:03,560 --> 00:04:09,160 Speaker 1: alopecia ariata, and a condition called telligent effluvium that makes 64 00:04:09,200 --> 00:04:12,760 Speaker 1: your hair fall out faster than normal. People can also 65 00:04:12,840 --> 00:04:17,320 Speaker 1: have brittle hair from hair shaft defects, or in rare cases, 66 00:04:17,640 --> 00:04:21,440 Speaker 1: they may even pull out their own hair compulsively if 67 00:04:21,440 --> 00:04:25,200 Speaker 1: they have a disorder called trick atilla mania. You think 68 00:04:25,240 --> 00:04:28,640 Speaker 1: that sounds scary. You can also lose your hair from illnesses, 69 00:04:29,000 --> 00:04:35,560 Speaker 1: fungal infections, burns, chemical applications, medications, and of course, cancer 70 00:04:35,600 --> 00:04:39,880 Speaker 1: treatments like chemotherapy. Smoking is also reported to increase the 71 00:04:39,960 --> 00:04:43,440 Speaker 1: risk of baldness. You should definitely see your doctor if 72 00:04:43,520 --> 00:04:46,080 Speaker 1: your hair starts falling out in clumps or if you 73 00:04:46,080 --> 00:04:56,039 Speaker 1: get a burning, itching irritation on your scout. Today's episode 74 00:04:56,080 --> 00:04:58,880 Speaker 1: was written by Christian and produced by Tyler Clang. If 75 00:04:58,920 --> 00:05:02,040 Speaker 1: you miss Christian, check out his new podcast dissecting pop culture. 76 00:05:02,279 --> 00:05:04,800 Speaker 1: It's called super Context and it's available wherever you get 77 00:05:04,800 --> 00:05:07,479 Speaker 1: your podcasts. And of course For more on this and 78 00:05:07,480 --> 00:05:09,960 Speaker 1: lots of other Harry topics, visit our home planet, how 79 00:05:10,040 --> 00:05:22,279 Speaker 1: stuff Works dot com.