1

Dehydration

"Anything that dehydrates the body can potentially cause similar feelings to a hangover," Dr. Greg Burrell, M.D., vice president of clinical product at health care service Carbon Health. For instance, simply forgetting to drink water while exercising can quickly lead to dehydration, says Ricanati, which can cause hangover-like symptoms like headache and fatigue.

Thankfully, it’s easy to feel better with adequate fluid replacement, she says. The general recommended daily water intake is 11.5 cups, or 2.7 liters, to stay properly hydrated. Drink more if you plan on exercising or if you’re sweating a lot on a hot day.

2

Too Much Caffeine

Did you double (or triple) your usual coffee intake for the day? According to Ricanati, over-caffeinating yourself might make you feel “off,” just like a hangover.

A typical cup of coffee contains 70 to 100 mg of caffeine. While there is no specific daily allowance for caffeine, a 2021 study recognizes that up to 400 mg a day is considered safe for people who don’t have health conditions. Any more than that, and you might start to experience other side effects, like increased anxiety.

To stay hydrated and offset any unwanted side effects, Ricanati recommends drinking a glass of water along with your morning cup of coffee.

3

Caffeine Withdrawal

On the flip side, if you recently cut back on your caffeine intake, it’s possible you’ll feel hungover as a result. A 2021 study found that caffeine withdrawal symptoms tend to set in 12 to 24 hours after your last cup, peak around the 20 to 51-hour mark, and may last from two to nine days.

Symptoms include everything from headache, fatigue, and decreased alertness, to depressed mood, difficulty concentrating, and feeling “foggy.” There’s also a risk of irritability, and all of these symptoms can range from mild to severe. Even if you only have one caffeinated beverage a day, going without can trigger withdrawal symptoms.

4

Stomach Viruses

According to Ricanati, dehydration can quickly set in after vomiting or diarrhea, so take note if you’ve recently had a gastrointestinal virus and feel symptoms of a hangover. Try to rehydrate — but, if you can’t keep fluids down, it’ll require a trip to the doctor.

5

Infections

Any type of infection — from the common cold to a urinary tract infection — can make you feel out of sorts, says Ricanati. Whether you feel achy, tired, or nauseated, she recommends checking in with your physician to figure out what’s going on.

6

Electrolyte Imbalances

A sports drink can save you from a pounding headache after a night of drinking, but that’s not the only reason to seek out a dose of electrolytes. If you have an electrolyte imbalance from exercising a ton or sweating a lot on a hot day, it can mimic the symptoms you might experience the morning after drinking.

"Any alteration in important electrolytes can affect one's mental and physical status, especially with sodium and potassium levels altered," says Dr. Ehsan Ali, M.D., an internal medicine specialist. To keep your body's mineral balance in check, make sure you stay hydrated, especially when working out, and ask your doctor about checking your vitamin and mineral levels if the feeling persists.

7

Sleep Medications & Supplements

It may make sense to take a sleep medication if you struggle to drift off to dreamland, but don’t be surprised if you wake up feeling groggy come morning. "Certain medications taken for sleep can cause next-day sedation or headaches," says Dr. Alex Dimitriu, M.D., a consultation psychiatrist and founder of Menlo Park Psychiatry & Sleep Medicine.

This is true for doctor-prescribed sleep medications, over-the-counter sleep aids, and even melatonin supplements. As always, check in with your doctor before trying anything new.

8

Antihistamines

There are many other medications that may lead to unwanted side effects, adds Ricanati, including antihistamines. These medications, which are used to reduce allergy symptoms, have the potential to cause headaches, dizziness, blurred vision, dry mouth, and even nausea and vomiting. Sounds just like a hangover, doesn’t it?

9

Sleep Deprivation

10

Anemia

When you have a hangover, you often want to stay in bed all day. And the same can be true if you’re anemic, says registered dietician Trista Best, MPH, RD, LD. She points to a condition called pernicious anemia, which is rooted in a vitamin B12 deficiency. “This is especially true as plant-based diets become more common, which is not a bad thing,” she tells Bustle. “It is just important to know how to eat a balanced, plant-based diet.” If you feel tired all the time for no reason, consider supplementing with this vitamin to improve your energy levels.

11

Migraine

If you get migraines, then you already know they’re way more than just a headache. But if you’ve never experienced one before, you might not be aware of how serious a migraine postdrome can be.

"Migraines, a special class of headaches, have been known to cause lingering hangover-like symptoms even after the migraine is over, known as a postdrome," says Burrell.

If you can trace your symptoms back to a severe headache, then it's possible this is the connection. "Light exercise, maintaining hydration, and avoiding overstimulation may help with this,” Burrell adds.

12

Pregnancy

Pregnancy causes a host of physical changes, including what you probably know as morning sickness. While that all-day nausea and fatigue can feel mighty similar to the morning after a night out, it’s actually caused by hormonal changes.

"A [pregnant] body will preference the baby, meaning that the first nutrients will go there, and the [parent] may end up feeling tired, dehydrated, or ‘hungover’ if [they are] not getting enough of those things," says Burrell.

13

Liver Or Kidney Problems

If you wake up feeling hungover relatively often, it could be a sign that one of your organs isn’t functioning properly. Ali points to liver and kidney problems as possible culprits, which can manifest with “altered physical and mental conditions.” If you experience chronic hangover symptoms, like nausea, fatigue, or even a decrease in your mental sharpness, let a doctor know ASAP.