Woke Up Feeling Hungover but Didn't Drink? This Might Be Why

The state of being “hungover” describes a feeling of general badness following a night of drinking. But what does it mean when you have all the symptoms and none of the drinking behaviors to explain them away?

Symptoms like dehydration, nausea or vomiting, headache, dizziness and fatigue are all classic signs of a hangover. But they're also common symptoms associated with a number of other problems.

Here are seven potential reasons you might be feeling hungover in the morning, even if you didn’t drink.

1. You're Dehydrated

Dehydration is actually one of the major culprits of an actual hangover, says Donna Casey, MD, an internist in Dallas, Texas.

Falling short on fluids can also lead to fluctuations in levels of the body's electrolytes like sodium and potassium, which can also cause hangover-like symptoms, Dr. Casey points out. Symptoms of an electrolyte imbalance include muscle aches, lightheadedness, heart palpitations, and weakness.

Tip: Start rehydrating by taking small, frequent sips of water, broth or an electrolyte-rich drink like Pedialyte or Gatorade, Dr. Casey recommends.

Resist the urge to chug. "Doing so will actually cause the body to excrete more fluid and perpetuate the problem," she says.

2. You've Got the Flu or Another Infection

A nasty bug can mimic symptoms of a hangover. "Much of this overlap is related to dehydration and electrolyte abnormalities," Dr. Casey says.

Too much booze can also irritate the lining of your GI tract and cause symptoms similar to a stomach bug like nausea or vomiting, as well as sweating, a fast heart rate, and skin flushing, she notes.

3. You Ate Too Much Sugar

Eating a lot of sweet foods at night can leave you feeling crummy the next day.

"Excessive sugar before bed can cause spikes and crashes in blood sugar to occur, which can lead to disruptive sleep and headaches, as well as feelings of shakiness, nausea or general fatigue," explains registered dietitian and certified diabetes educator Erin Palinski-Wade, RD, CDCES.

Keep in mind that "excessive" means different things to different people.

"We each respond to food and sugar in our own way. For some, it may take a large amount of added sugar to impact how we feel the next day," Palinski-Wade says. "For a person with insulin resistance or diabetes, just small amounts of added sugar can cause these feelings."

Tip: You can combat the effects of low blood sugar by drinking plenty of water and eating a balanced breakfast with lean protein, healthy fat and complex carbohydrates.

"Try scrambled eggs with mashed avocado on a slice of whole-grain toast," Palinski-Wade recommends. Some easy exercise like walking helps, too.

4. You're Going Through Caffeine Withdrawal

Whether you're trying to quit coffee or just didn't have time to get to your morning cup, skipping caffeine when your body expects it is a recipe for feeling awful.

"Symptoms related to caffeine withdrawal include primarily headache, but it may manifest with drowsiness or sluggishness, brain fog, irritability, difficulty concentrating, decreased alertness and depressed mood," Dr. Casey says. "And at the extreme end, it can include nausea, vomiting, and muscle aches."

Tip: If you're cutting out caffeine on purpose, you'll minimize symptoms of withdrawal by dropping your consumption gradually, Dr. Casey says. Try trimming back by just a few ounces each day instead of going from a full cup of coffee to nothing at all.

5. You Took Sleeping Meds

Tip: Talk with your doctor if your sleeping medication is causing hangover-like side effects the next morning. It may be possible to adjust your dose or try a different drug.

6. You Have Migraine

Alcohol is a common migraine trigger. But even without drinking, waking up with migraine can feel a lot like the morning after a night of heavy boozing.

7. You're Pregnant

Tip: For nausea relief, try sucking on ice chips or popsicles to stay hydrated and stick with small, frequent meals instead of bigger ones, recommends ob-gyn Felice Gersh, MD, founder and director of the Integrative Medical Group of Irvine in California.

You can also ask your practitioner about taking 50 milligrams or less of vitamin B6 daily, which may help ease symptoms of morning sickness, she says.

When to Call the Doctor

Sometimes hangover-like symptoms have a relatively benign cause and a simple fix, like being mildly dehydrated or having a sugar feast before bed. But other times they could be a sign that something is wrong, especially if you wake up feeling hungover without drinking more than once.

If you can't pinpoint an obvious cause for why you're feeling so lousy, and can't ease your symptoms with simple at-home measures (like drinking more water or resting), call your doctor, Dr. Casey recommends.

"The symptoms could be indicative of another severe illness or severe dehydration that requires immediate medical attention," she says.

The Takeaway

• Not drinking enough water, consuming too much sugar, or experiencing caffeine withdrawal can all lead to hangover-like symptoms.
• The flu or other illnesses, as well as certain sleeping pills or antidepressants, can also mimic a hangover.
• If you frequently feel hungover without drinking and simple remedies don't help, consult a doctor to rule out underlying medical conditions.