According to the American Academy of Sleep Medicine, more than 30 percent of adults have experienced insomnia in some form. But when it comes to symptoms, causes, and treatments, the disorder is far from one-size-fits-all. Read on to find out more about what it is, what to do about it, and why you shouldn’t try out Vincent van Gogh’s go-to insomnia cure for yourself.

1. There’s more than one type of insomnia.

Difficulty drifting off at the start of the night—called sleep onset insomnia—is probably what many people think of when they hear the word insomnia. But it’s not the only kind. If you find yourself waking up throughout the night and having a tough time falling back asleep, that’s sleep maintenance insomnia. And if you often wake up much earlier than you need to and can’t fall back asleep, you may have early morning awakening insomnia (according to the Sleep Foundation, this is sometimes considered a subset of sleep maintenance insomnia rather than its own category).

Insomnia can be labeled by how many nights it lasts, too. Chronic insomnia describes sleep struggles that occur at least three nights every week over a three-month period or longer. Anything less than that is usually considered acute insomnia (also called short-term insomnia or adjustment insomnia).

2. Insomnia symptoms can go beyond trouble falling asleep.

The ways that an insomnia-related lack of sleep can affect you during waking hours are also considered symptoms of insomnia. This could be as simple as feeling drowsy or tired during the day. Or, as the Mayo Clinic explains, you may experience “irritability, depression or anxiety,” “difficulty paying attention, focusing on tasks or remembering,” “increased errors or accidents,” and/or “ongoing worries about sleep.”

3. Some insomnia causes are habit-related.

That afternoon flat white might not help you in the long run.djgunner/iStock via Getty Images

Drinking caffeinated beverages too late in the day, staring at your phone (or any screen) while you’re trying to fall asleep, or having a large meal right before bed can cause insomnia. If you habitually have alcohol before bed to help you drift off, it could be doing more harm than good—alcohol can inhibit REM sleep and prevent you from staying asleep throughout the night.

A person’s insomnia may also be related to a preexisting medical issue. This could be another sleep disorder, like sleep apnea or restless legs syndrome; a mental health disorder like anxiety, depression, or post-traumatic stress disorder; or a condition like asthma, chronic pain, or Parkinson’s disease. Medications taken to treat those issues may also contribute to insomnia.

Stress is another very common cause of insomnia, whether it’s brought on by worries about regular parts of life—money, work, relationships, etc.—or a specific traumatic event, like losing your job or a death in the family.

4. Fatal familial insomnia is—true to its name—a deadly sleep disorder.

The usual cause of fatal familial insomnia (FFI), on the other hand, is an abnormal variant in the PRNP (prion protein) gene. Basically, the variant causes prion proteins to fold improperly, which build up in the thalamus and start to knock out nerve cells. One of the main symptoms of this brain damage is insomnia, which often intensifies over a period of months. FFI is a rare degenerative disease—but it is deadly. According to NIH's Genetic and Rare Disease Information Center, patients usually pass away somewhere between six months and three years after onset.

5. Not all insomnia treatment involves sleeping pills.

There’s no dearth of medication on the market that may alleviate your insomnia, from prescription sleeping pills like Lunesta and Ambien to over-the-counter supplements like melatonin. But while medication can help you sleep on a night-by-night basis, it won’t help you identify what’s causing your insomnia and cut it off at the source.

Cognitive behavioral therapy for insomnia (CBT-I) can. As the Mayo Clinic explains, “the cognitive part of CBT-I teaches you to recognize and change beliefs that affect your ability to sleep,” while the behavioral part “helps you develop good sleep habits and avoid behaviors that keep you from sleeping well.” Since all those elements vary from person to person, a sleep therapist will work with you to devise a personalized course of action. This could mean improving your “sleep hygiene,” which involves making lifestyle changes like decreasing caffeine consumption or increasing exercise; learning meditation and muscle relaxation techniques; or trying any of these other common CBT-I methods.

6. Historical cures for insomnia included dog earwax and dormouse fat.

"Dormouse what on your feet?"LenSoMy/iStock via Getty Images

Some ancient Romans thought rubbing dormouse fat on your feet could help you sleep. Not an appealing prospect, but also not as bad as Renaissance mathematician Gerolamo Cardano’s recommendation that insomniacs coat their teeth with dog earwax. Another old insomnia “cure” was a concoction containing bile from a castrated boar (along with opium, which definitely helped more than the boar’s contribution).

7. A few people have claimed to have functioned fine for decades with no sleep.

In 1915, a Hungarian soldier named Paul Kern suffered a bullet wound to the head while fighting in World War I, after which he was allegedly never able to sleep again. “Curiously, apart from an occasional headache, M. Kern suffers no ill effects. He has not gone to bed for years, and his work reveals not the slightest signs of deterioration,” The Adelaide Chronicle wrote in 1930. Kern lived until 1955. New Jersey’s Albert Herpin—who died in his nineties in 1947—and Thái Ngọc, a Vietnamese farmer who’s now in his late seventies, have both also made headlines for surviving decades supposedly without sleeping a wink.

It’s unclear whether those men were true medical anomalies, intentional exaggerators, or just unaware that they were, in fact, occasionally asleep. Often, people who go too long without sleeping start “microsleeping”—falling asleep for seconds at a time without even realizing it. If you tried to avoid sleep for as long as possible, it would likely only take a few days for it to seriously affect your cognitive and motor abilities. The world record for sleeplessness is just 264 hours—about 11 days—and record-setter Randy Gardner started hallucinating not even halfway into it.

8. Franz Kafka and Vincent van Gogh both suffered from insomnia.

Franz Kafka, Vincent van Gogh, Abraham Lincoln, Marilyn Monroe, Groucho Marx, and Margaret Thatcher are several of many prominent figures who sometimes struggled to sleep. “Sleepless night. The third in a row,” Kafka wrote in his diary on October 2, 1911. “I fall asleep soundly but after an hour I wake up, as though I had laid my head in the wrong hole.”

Van Gogh mentioned his issues with insomnia in a letter to his brother, Theo, from January 9, 1889—just weeks after he cut off his ear. “Physically I am well,” he wrote. “What is to be feared most is insomnia, and the doctor has not spoken about it to me, nor have I spoken of it to him either. But I am fighting it myself.” His self-administered treatment was “a very, very strong dose of camphor in my pillow and mattress.” (Camphor can be toxic or even fatal when ingested, so don’t follow van Gogh’s lead on this.)