1. Random sharp pains You’re minding your own business when suddenly it feels as if someone’s stuck you with a pin. Then the feeling goes away, never to return. “It’s the hypochondriac’s muse,” says Marcela Espinosa, MD, an internal medicine physician with HealthCare Partners Medical Group in Los Angeles. “Sharp pains that last for a second or two then go away are something we all experience from time to time and are usually benign.” If the pain returns or increases in intensity, it’s best to see a doctor.
  2. Hiccups that make it hard to talk Chewing gum, drinking soda, and eating to excess can all trigger hiccups. What happens is that muscles in your upper chest suddenly contract and you take in air, then your voice box closes, creating the “hic” sound, says Espinosa. “Most hiccups go away on their own or after drinking a glass of water. They’re usually harmless, unless they don’t go away, which signals a condition called ‘intractable hiccups,’ which is rare.” See a doctor if this happens. Otherwise deep, slow breathing to relax the muscles should help.
  3. Jerking awake just as you start to fall asleep You’re just dozing off when bam! You wake up suddenly. Called “hypnagogic or hypnic jerks,” the sensation results from sudden brief muscle contractions and affects up to 70% of the population, says Allen Towfigh, MD, medical director of New York Neurology & Sleep Medicine. “These occur as the brain transitions the body from wakefulness to sleep. Hypnic jerks can happen when you’re sleep deprived or stressed.” They’re usually not anything to worry about unless they occur frequently, which requires further investigation. MORE: Sleeping THIS Many Hours A Night Could Mean Your Stroke Risk Is 46% Higher
  4. Yawning when someone else yawnsPLOS ONE Yawning when you see another person yawn (or even when you read this paragraph about yawning) is common and is not linked to tiredness or energy levels, according to a study published in the journal . The study, which involved 328 participants, confirmed that some people are more susceptible to contagious yawning than others. Overall, 222 of the participants yawned contagiously at least once. Interestingly, contagious yawning decreased with age but did not appear to link to empathy or time of day, as previously believed.
  5. Your nose bleeding out of nowhere Nosebleeds are usually scarier than the root cause, says Espinosa. “They typically occur because of dry nasal passages (like on airplanes) or picking your nose.” Irritation due to allergies, cold, sneezing, blowing your nose too hard or overuse of decongestant nasal sprays can also trigger a nosebleed, since small blood vessels in the nose bleed when irritated. “Most stop on their own,” says Espinoza. To halt the flow, keep your head forward, and squeeze just below the bony part of your nose and hold for 10 minutes before checking to see if the bleeding has stopped. If it doesn’t stop within an hour, go to an emergency clinic.
  6. Sneezing in bright light If looking at light reflecting off snow makes you sneeze, you’ve experienced a photic sneeze reflex. “We think this occurs when wires in the brain are crossed,” says Sandy T. Feldman, MD, medical director of ClearView Eye & Laser Medical Center in San Diego. “The trigeminal nerve is responsible for sensation of the eye as well as the nose, but through different branches. In the case of a photic sneeze reflex the light is mistaken by the brain as an irritant to the nose.” A genetic trait, most people with photic reflex sneeze one to three times in succession, but it can be up to 40! MORE: This Is How Far Your Sneeze Travels
  7. Feeling “twitchy” A rapid muscle twitch in your arm or leg—or even your eyelid—is quite common and not anything to worry about, says Espinoza. Caused by minor muscle contractions in one area, most go unnoticed. Lack of sleep, stress, exercise, and anxiety can worsen or trigger twitches, but they usually go away after a couple days. “They can also be a sign of an autoimmune disease or a side effect of a medication such as an antidepressant or estrogen,” says Espinoza. See a doctor if the twitching persists or is accompanied by muscle weakness.
  8. Walking in your sleep Medically known as somnambulism, sleepwalking may seem harmless and even humorous, but it’s one of the leading causes of sleep-related injury, says Towfigh. Episodes can last from a few seconds to longer than a half hour and are usually characterized by unresponsiveness to the environment, mental confusion, and varying degrees of amnesia following the event or the next morning. “Seizures and other complex disorders such as REM-sleep disorders can cause similar symptoms, therefore it’s important to seek the help of a sleep specialist or medical professional,” says Towfigh. MORE: 7 Ways To Fall Back Asleep In 10 Minutes Or Less