40 Fun Facts About Men's Health

Which pair of glands, sitting behind the bladder, produces 70 to 85% of the fluid in the ejaculate?

The seminal vesicles supply 70 to 85% of seminal fluid, dwarfing the testicles' own contribution. Their fructose-rich secretion is what fuels the sperm on the way out.

Melanoma most often appears on which part of a man's body, whereas in women it favours the legs?

The back is the most common melanoma site in men, a spot nobody can inspect in a mirror. In the United States melanoma occurs about 1.6 times more often in men than in women.

Red–green colour blindness affects roughly what share of men of Northern European descent, against 0.5% of women?

About 8% of such men, one in twelve, are red–green colour blind because the opsin genes sit on the X chromosome. A man has only one X, so a single faulty copy is enough.

About 27% of men but only 3% of women develop which hernia, passing through the canal the testicles descend along?

The inguinal hernia is roughly 25 times more likely in men because the canal that carried the testicles down in infancy leaves a wider gap in the abdominal wall. Repairing it is among the most common operations in the world.

Movember's founding event, 30 men growing a moustache for 30 days, was organised in which Australian city?

Melbourne hosted the 30-man moustache challenge that grew into a global charity, though a separate Adelaide group had coined the word 'Movember' on the news in 1999. The name fuses 'mo', Australian slang for moustache, with the month.

Gout, which mostly strikes older men and hits the big toe in half of cases, is caused by crystals of which substance?

Needle-shaped crystals of uric acid, a waste product of digesting purines, lodge in the joint and trigger the attack. Its link to rich food and drink earned gout the nickname 'the disease of kings'.

Testicular cancer, which most often begins between the ages of 20 and 34, has what five-year survival rate in the US?

About 95% of American men diagnosed with testicular cancer are alive five years later, one of the best outcomes of any cancer. Germ cell tumours of the testis are nonetheless the most common cancer in men aged 15 to 35.

To gauge fat carried around the middle, the NHS advises keeping a man's waist below what?

Half his height is the NHS line: for a 180 cm man that means a waist under 90 cm. The NHS offers the ratio as a check for anyone with a BMI under 35, because belly fat carries risk that BMI alone misses.

Symptoms of coronary artery disease, the world's top killer, typically appear how much later in women than in men?

Women generally develop symptoms 10 years later than men, which is why the disease long wore a male reputation. In 2015 it accounted for 15.6% of all deaths worldwide, more than any other single cause.

In the Western world, men die by suicide how much more often than women, who attempt it more often?

Men die by suicide three to four times more often than women in the West, even though women make two to four times as many attempts. Researchers call this the gender paradox and tie much of it to men choosing more lethal methods.

The NHS advises men, exactly like women, to keep regular drinking under what weekly alcohol limit?

The limit is 14 units a week for both sexes, about six pints of average-strength beer, after the old higher allowance for men was scrapped. The advice is to spread that across three or more days rather than one sitting.

What does the Movember charity call the men who sign up to grow a moustache for it every year?

Mo Bros are the charity's moustache-growers, and the money they raise goes to three causes: prostate cancer, testicular cancer, and mental health and suicide prevention. Women who support them are Mo Sistas.

Autopsy studies find benign prostate growth in half of men over 50; what share shows it after age 80?

Some 80% of men past 80 have benign prostatic hyperplasia on autopsy, making it close to a normal feature of ageing. Because the gland wraps the urethra, its growth explains the weak stream and night-time trips to the toilet.

PSA, the protein measured in prostate screening blood tests, does what job in the ejaculate?

PSA liquefies semen after ejaculation so sperm can swim free of the initial gel. Only a trace normally leaks into the blood, which is why a rising level draws attention.

On average, adult men carry roughly what multiple of the testosterone level of adult women?

Men have about 7 to 8 times as much testosterone as women, but women make it too, in the ovaries and adrenal glands. In men nearly all of it comes from the testicles.

By the age of 50, pattern hair loss affects what share of men, compared with a quarter of women?

About half of men show pattern hair loss by 50, and some 80% of bald men got it from a bald dad. The idea that it comes only from the mother's side does not survive the numbers.

What is the first physical sign of puberty in boys, who start at 11½ to 12, about a year after girls?

Testicular enlargement, termed gonadarche, comes first; the voice drops about an octave later on as the vocal folds lengthen and thicken. Girls typically begin around age 10½.

After a vasectomy, what happens to the sperm that the testicles carry on producing?

The body absorbs them: sperm are still made but are broken down, with fluid taken up in the epididymis and solids cleared by macrophages into the bloodstream. The testicles keep making testosterone exactly as before.

The epididymis, the coiled tube on each testicle where sperm mature, would stretch roughly how far if uncoiled?

Uncoiled, the epididymis runs about 6 metres, packed onto a gland the size of a walnut. Sperm take two to six days to travel its length while they learn to swim.

From the first cell division to a mature cell, making a single human sperm takes roughly how long?

Spermatogenesis takes about 74 days, yet the testicles turn out 200 to 300 million sperm every day of adult life. Only around half of those are viable.

Which muscle hoists the testicles toward the body in the cold, keeping them near the 34.5 °C that sperm need?

The cremaster raises and lowers the testes to hold them 2 to 2.5 °C below core temperature. Stroking the inner thigh fires the cremasteric reflex, lifting the testicle on the same side.

What share of full-term baby boys are born with an undescended testicle, most of which drop within a year?

About 3% of full-term boys have at least one undescended testis at birth, but the figure is 30% among premature boys. Roughly 80% descend on their own within the first year.

Which cells in the testicles, named after the German anatomist who found them in 1850, produce testosterone?

Leydig cells, discovered by Franz Leydig, sit between the seminiferous tubules and make testosterone when luteinising hormone arrives from the pituitary. Sertoli cells next door nurse the developing sperm instead.

Which two-surname scale grades male pattern baldness by severity, from a receding hairline to a bare crown?

The Hamilton–Norwood scale is the standard chart for grading male androgenic alopecia. The enzyme that converts testosterone into its follicle-shrinking form is most active in two tissues: the scalp and the prostate.

Which hormone, made from testosterone by 5-alpha-reductase, drives male pattern hair loss and prostate growth?

DHT, dihydrotestosterone, binds the androgen receptor several times more strongly than testosterone itself, which is why the scalp and prostate answer to it.

Minoxidil, approved for baldness as Rogaine in 1988, had first reached the market in 1979 as an oral tablet for what?

Minoxidil was a high blood pressure drug called Loniten until patients on trial kept sprouting hair, a side effect a Miami dermatology resident first reported. Rubbing it on the scalp turned the nuisance into the product.

Finasteride, licensed for hair loss as Propecia in 1997, had first been approved five years earlier to treat what?

An enlarged prostate, benign prostatic hyperplasia, was the original target: Merck sold it as Proscar from 1992. The hair-loss version is the same molecule under a different name.

National Prostate Health Month, designated for September in 1999, is symbolised by a ribbon of which colour?

A light blue ribbon marks prostate awareness each September in North America, two months before the moustaches of Movember. The American Foundation for Urological Disease chose the month.

Men's Health Week, created by the US Congress in 1994, is the week ending on which day each June?

Father's Day closes the week, a deliberate nudge to get men checked while families are already thinking about them. The bills were sponsored by Bob Dole and Bill Richardson, and the week went international in 2002.

International Men's Day, held each 19 November, was first observed in 1999 in which Caribbean country?

Trinidad and Tobago held the first International Men's Day, conceived by Dr Jerome Teelucksingh of the University of the West Indies. He chose the date partly because it was his dad's birthday.

Which 72-year-old physiologist told a Paris society in 1889 that animal testicle extract had rejuvenated him?

Brown-Séquard's claim that the extract prolonged life sent thousands of men chasing the 'elixir', yet the fluid could not have carried a meaningful hormone dose. Any benefit was almost certainly placebo.

Which Chicago surgeon won the 1966 Nobel Prize for showing that castration shrank advanced prostate tumours?

Charles Huggins proved a cancer could be controlled by starving it of a hormone, and patients in agony reported relief within days. His was only the second Nobel ever given for cancer research, shared with Peyton Rous.

Richard Ablin, who discovered PSA in 1970, has argued for nearly as long that the test should not be used for what?

Routine screening of healthy men is what its own discoverer opposes, because PSA rises with a harmless swollen gland as readily as with cancer. He has accused the FDA of approving it for screening despite its advisers' warnings.

Klinefelter syndrome, found in 1 in 500 male births but diagnosed in only a quarter, involves which chromosome pattern?

XXY men carry 47 chromosomes instead of 46, and most never find out, often until a fertility clinic counts them. It is among the most common chromosomal conditions in males.

Which intronless gene on the Y chromosome switches on SOX9 and turns an embryo's gonads into testes?

SRY, the sex-determining region of the Y, is a transcription factor that kicks off a cascade of other genes; without it the same gonads become ovaries. Every embryo starts down the female path until this switch flips.

Worldwide, about how many boys are born for every 100 girls, before higher male mortality evens the numbers out?

Around 105 boys arrive for every 100 girls, a ratio that holds across most of the world. By the over-65s it has flipped to 0.81 men per woman, and in Russia to 0.46.

WHO and UNAIDS backed voluntary medical male circumcision in 2007 after trials showed what cut in men's HIV risk?

Circumcision cuts a man's risk of catching HIV from a female partner by about 60%, and more than 27 million procedures have followed in 15 priority countries of eastern and southern Africa. Worldwide, 37 to 39% of men are circumcised.

A varicocele, swollen veins in the scrotum found in around 15% of men, is the most common correctable cause of what?

Male infertility traces to a varicocele in 35 to 44% of men with primary infertility, and 80 to 90% of them sit on the left. The left vein drains into the renal vein at a right angle, so blood backs up there.

A 2017 meta-analysis found sperm counts among Western men fell by roughly what share between 1973 and 2011?

Counts dropped 50–60% over those four decades, about 1.4% a year, and nobody has settled on why: chemical and pesticide exposure, maternal smoking in pregnancy and adult lifestyle are the suspects.

Up to what share of adolescent boys develop gynecomastia, a swelling of breast tissue, during puberty?

Up to 70% of boys get some gynecomastia in puberty, and three quarters of cases fade within two years untreated. It returns in later life, affecting 35% of men, most often between 50 and 69.