Why do I feel so much worse after a nap – and how can I avoid it?

The Guardian

a day ago

I woke up on the couch feeling nauseous and groggy, with a needle-jabbing-my-temples headache. Was it the flu? Did I eat something bad? There was drool on my cheek, and I glanced at the clock. I remembered checking the time at 1.30 pm; it was now 4pm.
I'd accidentally taken a nap.
Many people say there's nothing like a good nap – but not me. It always gives me stomach-turning nausea, usually for the rest of the day.
So I do my best to avoid dozing, even when I need the rest. In college, I'd power through even if I pulled an all-nighter. But now, as a mom, my no-nap lifestyle is more difficult to maintain. I feel like I'm playing real-life 'would you rather': zombie-tired from staying up all night with my crying baby or spin-cycle sick?
Dr Waiz Wasey, a Mayo Clinic-trained sleep physician based in Scottsdale, Arizona, says symptoms such as nausea, dizziness and lightheadedness after a nap are common. These can vary from mild to day-ruining, and could have different causes. Because of this, he says, treatment isn't one-size-fits-all.
There are several reasons people might experience nausea, dizziness or a generally unwell feeling after a nap.
Sleep inertia: Wasey says sleep inertia, characterized by dizziness, lightheadedness, nausea and disorientation, is one of the main reasons people feel sick after taking a snooze.
Sleep cycles typically last about 90 minutes, which includes three sleep stages plus REM sleep. People usually go through three or four sleep cycles per night, but when nappers wake without completing a full cycle, they may experience unpleasant, often disorienting, symptoms, he says.
Most cases of sleep inertia are mild and resolve on their own after about 20 minutes, says Dr Funke Afolabi-Brown, a triple-board-certified sleep medicine physician based in Philadelphia. But extreme cases can involve 'debilitating symptoms lasting four to six hours, sometimes with vomiting or panic-like symptoms'.
Sleep inertia isn't nap-specific: it can also happen when you wake from a night's sleep. But this is less common, says Wasey, as someone who has completed a few sleep cycles feels more restored upon waking.
Symptoms also tend to be more severe after a nap because of your body's circadian rhythm, or natural daily sleep cycle. 'Your body isn't expecting to sleep in the afternoon,' Afolabi-Brown says. 'Morning grogginess usually resolves within 15-30 minutes, while post-nap symptoms may persist longer.'
Wasey notes that people who have sleep apnea, insomnia or sleep deprivation are more likely to experience more extreme symptoms of sleep inertia.
Gastrointestinal issues: Acid reflux – also called gastroesophageal reflux or heartburn – is a common cause of nausea, dizziness and chest pain after resting, says Dr Bharat Pothuri, a board-certified gastroenterologist based in Houston, Texas. It is characterized by stomach acid traveling into the esophagus, and lying down after eating makes it worse, says Pothuri.
Just about everyone will experience some acid reflux now and then, Pothuri adds, especially after eating fatty or acidic foods. But some experience more severe symptoms. About 20% of the US population is affected by frequent acid reflux, or gastroesophageal reflux disease (also known as Gerd), and is more likely to experience nausea after lying down.
Stomach issues can show up after a full night's rest, but it's especially common for daytime snoozers because they may lie down directly after lunch or a snack.
Dr Rucha Mehta Shah, a board-certified gastroenterologist in Scottsdale, Arizona, says diet plays a role. 'Certain foods like fatty, fried, creamy, dairy or high-fiber foods can sit longer and cause more symptoms,' she says.
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Other causes: Dehydration and low blood sugar can make a person feel unwell upon waking, says Wasey. Sleep apnea, a condition where one's breathing stops and starts abruptly during sleep, can cause symptoms such as headaches, sore throat and even anxiety. 'Disruptions in breathing can lead to drops in oxygen levels that can trigger headaches, dizziness, and nausea,' he explains.
Less common issues include dysautonomia, the inability to regulate involuntary body functions such as heart rate and blood pressure, and benign paroxysmal positional vertigo, characterized by dizziness after your head changes positions, such as lying down or sitting up in bed.
If you suspect any of these, Wasey says to talk with a doctor.
A short slumber is a safe bet.
'We always encourage naps to be brief: 20 minutes or less,' says Wasey. 'If a nap is more than 20 minutes, it can go into deep sleep. If they wake during deep sleep, they're more likely to experience unpleasant symptoms upon waking.'
If a quick lie-down doesn't seem like enough, give yourself time to complete one full 90-minute sleep cycle. 'I tell patients to either do a 20-minute or a 90-minute nap,' he says.
If GI issues are causing problems, keep the nap under half an hour, says Pothuri. The digestive system tends to slow down after 20 minutes of sleep, which means food stays in the stomach longer. Plus, less horizontal time means less time for stomach acid to irritate the esophagus.
Keep naps short, says Wasey – or skip them altogether. It helps to have a good night's rest, he says: 'Start a bedtime routine by winding down, reading a book or meditating, and limit blue light one to two hours before actual bedtime.'
Afolabi-Brown says that if you take a nap, doing so earlier in the day can help ensure you don't have trouble sleeping at night. Snoozing too long or too late in the day can reduce your sleep drive, the pressure to sleep that builds in our bodies the longer we're awake.
If you suspect GI issues, Shah recommends waiting until your food has digested before lying down – ideally three to four hours. If that's not realistic, try to avoid spicy, acidic and fatty foods before napping. And when you lie down, prop yourself up with pillows or an adjustable mattress. 'We want to work with gravity,' says Shah. 'Keeping the head and chest elevated will mean less acid injury to the lower part of the esophagus.'
Over-the-counter antacids can alleviate symptoms, but if discomfort persists, Shah recommends seeing a doctor. Prescription medications may provide more relief, or a physician may want to check for other issues in the esophagus, such as infection, ulcers or esophagitis.
After speaking with the experts, I set aside a day to try their advice. I kept breakfast and lunch simple, swapping an acidic orange for toast and ignoring lasagne leftovers in favor of a light salad. When my son went down for a nap, I made a mini mountain of pillows to prop myself up and set an alarm for 20 minutes. When I woke up, I felt refreshed, rested and happy – no nausea or brain fog.
I don't always have the forethought to avoid triggering foods or arrange pillows. But thanks to these adjustments, I've discovered that there really is nothing like a good nap.
Jillian Pretzel is a freelance journalist in Southern California