Why is "hysterical" applied to women but rarely to men?

hysterical :  affected by or deriving from wildly uncontrolled emotion, Janet became hysterical and began screaming.

Why is the adjective hysterical usually applied to women and rarely to men?

For what it's worth, Google Books shows 42,700 hits for hysterical woman and 2,820 hits for hysterical man, but the fact is I rarely hear hysterical used in reference to men.

Because men can't have hysterectomies. The words "hysterical" and "hysterectomy" share the same root in the word for "uterus". In Victorian times, the root of female issues was theorized to be a non-existent medical condition some physicians called "wandering womb". This now-debunked belief is widely regarded as a form of medical quackery, but on the upside, it led to the invention of the vibrator, which was regarded as a cure for hysteria, especially when wielded by the skilled hands of an expert physician. Because those skilled hands got mighty tired after a half-day of administering treatments to patients, and they needed a break.

Yes, this really happened.

As pointed out by @Linda, etymologically speaking, hysteria is a neurotic condition peculiar to women and thought to be caused by a dysfunction of the uterus. But very few people think of the word that way when they use it today.

I think OP massively overstates the case regarding how rarely the word hysterical is applied to men. It just so happens "hysterical woman" is a [cliched, sexist] stereotype. With he/she was hysterical, or he's/she's hysterical, for example, the "skew" is closer to 2:1 than OP's 15:1.

Note that by far most common usage in recent decades is the even more figurative informal hysterical = extremely funny...

He was hysterical (about 26,100 results in Google Books)
She was hysterical (99,300)
It was hysterical (280,000)

As an addendum to the "hysterical meaning funny" discussion:

The best practical definition of hysteria is "someone that lets fear/any other strong emotion break out-of-control, and then starts to look for a cause". The "looks for a cause" part means autosuggestion. An example is that people react irrationally and out of proportions: cry, laugh, etc.

I believe that's the origin of its usage to mean funny, e.g. "John was hysterical last night". The exaggerated actions of John certainly caused people around him to react by laughing/smiling. There are many movies that make jokes over hysteria (Airplane! comes to my mind) exploiting those irrational and exaggerated reactions.

In some cases, hysteria can lead to a "conversion disorder" which is also called "conversion hysteria", and is essentially when a person develops physical symptoms based on psychological effects.

As to why it is used mostly in reference to women, see FumbleFingers' or LindaBrammer's answers.

This is the origin of hysterical (adj.)

1610s, "characteristic of hysteria," from Latin hystericus "of the womb," from Greek hysterikos "of the womb, suffering in the womb," from hystera "womb".

The word hysteria originates from the Greek word for uterus, as it was thought this disorder (eg. anxiety, nervousness) could only be found in women.

In Ancient Greece, the womb was regarded as a living creature in a woman's body, which wanders around and causes the disorder. The cure for hysteria was to put the womb back to its correct place by inhaling some good smells.

In the 16th and 17th centuries, people continued believing the disorder was related to the womb, though the reasons changed a little: Hysteria was now believed to be due to retention of fluids in the uterus, sexual deprivation, or still by the tendency of the uterus to wander around the female body causing irritability and suffocation. This is the time the word hysterical emerged.

By the Industrial Era, people recognized that hysteria is a psychological condition rather than a physical one, and that men can also be hysterical. The word hysteria emerged in 1801 and started to have a general sense of "unhealthy emotion or excitement" by 1839.

In modern time, the word hysterical was used against the campaign for women to fight for rights and empowerment.