Nausea is the feeling that you’re going to throw up. You often have other symptoms like diarrhea, sweating, and abdominal pain or cramping along with it.

According to the American Pregnancy Association, nausea affects more than half of all pregnant women. Commonly known as morning sickness, it’s caused by hormonal changes that occur during the first trimester of pregnancy.

While pregnancy may be the best-known cause of morning sickness, it isn’t the only one. Keep reading to find out about other conditions that can leave you feeling queasy in the morning.

Both men and women can wake up feeling nauseated.

Pregnancy

Nausea and vomiting are among the earliest signs of pregnancy, appearing around the sixth week. These symptoms usually go away between weeks 16 and 20.

Morning sickness isn’t limited to the morning. It can happen at any time. Some women experience ongoing nausea throughout the day.

Fatigue or sleep issues

Jet lag, insomnia, or an earlier-than-usual alarm can disrupt your sleep-wake cycle. These changes in your regular sleeping pattern shift your body’s neuroendocrine response, which can sometimes lead to nausea.

Hunger or low blood sugar

If the last time you ate was at dinner, 12 or more hours may have passed by the time you wake up in the morning. A low level of glucose in your blood (low blood sugar) can leave you feeling dizzy, weak, or nauseous. Skipping breakfast — especially if you usually eat breakfast — may make it worse.

Acid reflux

Acid reflux occurs when the entrance to the stomach doesn’t close properly after you eat or drink, letting stomach acid escape into the esophagus and throat. The sour taste, along with other symptoms such as burping or coughing, can leave you feeling nauseated.

Acid reflux can be worse in the morning, even though it’s been hours since you last ate. This might be because you’re in a reclined position and swallow less when you’re sleeping.

Postnasal drip or sinus congestion

Sinus congestion puts pressure on your inner ear, which can lead to an upset stomach and nausea. It can also cause dizziness, which can cause nausea and vomiting. When you have postnasal drip, mucus that drains from the sinuses to the back of the throat and into the stomach can cause nausea.

Anxiety

We often feel emotions such as stress, excitement, and anxiety in our gut. Nausea in the morning might be related to a stressful event, such as an upcoming important meeting. In other cases, it’s caused by chronic or ongoing sources of stress or anxiety.

Hangover

If you had a lot of alcohol to drink the previous night, your nausea might be the result of a hangover. A number of alcohol’s effects are associated with nausea. These include low blood sugar and dehydration.

Diet

Nausea in the morning could be related to something you ate at breakfast. A mild food allergy or intolerance can cause nausea. In other cases, eating too much will leave you feeling nauseated.

Gastroparesis

Gastroparesis is a condition in which the muscles in the wall of your stomach slow down or stop. As a result, food does not move from your stomach to your intestine. Nausea, vomiting, and abdominal pain are common symptoms.

Gallstones

Gallstones form in your gallbladder when substances, such as cholesterol, harden. When they get stuck in the tube that connects the gallbladder and intestine, it can be very painful. Nausea and vomiting often occur with the pain.

Pain medication

Opioids are a class of drugs used to treat moderate to severe pain. A side effect of most of these drugs is nausea and vomiting.

Chemotherapy

Nausea and vomiting are well-documented side effects of some chemotherapy drugs. The drugs turn on the part of your brain that controls nausea and vomiting. Sometimes the drugs also affect cells in the lining of your stomach, which can cause nausea and vomiting.

If you’ve already had nausea and vomiting from receiving chemotherapy, just the sights and smells that remind you of it can trigger nausea and vomiting.

Brain injury or concussion

Concussions and brain injuries can cause swelling in your brain. This increases the pressure in your skull, which can turn on the place in your brain that regulates nausea and vomiting. Vomiting after trauma to your head indicates your head injury is significant and you should seek immediate medical attention.

Food poisoning

When you eat or drink something that is contaminated, your body works quickly to get rid of it. If you have food poisoning, you might experience nausea, vomiting, or diarrhea, along with an upset stomach or abdominal cramps. If you’re experiencing nausea in the morning, it could be something you ate the previous night.

Gastroenteritis

Gastroenteritis is not the same as food poisoning, though it causes similar symptoms. This infection is caused by a virus, bacteria, or parasite. It’s transferred from person to person via contaminated feces, food, or drinking water.

Diabetic ketoacidosis

Diabetic ketoacidosis is a serious complication that can occur when you have diabetes and insulin scarcity forces the body to start breaking down fats (instead of carbs) to use as fuel.

This process results in a buildup of ketones in the bloodstream. Too many ketones can cause symptoms such as nausea, confusion, and extreme thirst. You should seek emergency medical assistance right away if this happens.

Peptic ulcer

Peptic ulcers are sores that affect the inner lining of the stomach and intestines. They typically cause stomach pain, but they can also cause nausea and vomiting.

Constipation

Constipation can cause nausea. When digested matter is backed up in your colon, it slows down the function of your entire gastrointestinal system, leading to nausea.

Motion sickness

Motion sickness happens when your brain gets mixed signals about your movement. For example, when you ride in a car, your eyes and your ears tell your brain that you’re moving but the area in your inner ear that helps you stay balanced, and your muscles, tell your brain that you aren’t moving. The mixed signals can cause nausea, vomiting, and dizziness. This happens most often in pregnant women and children.

Inner ear infection

The vestibular system in your inner ear helps your body stay balanced. When you have an infection in your inner ear, it can make you feel unbalanced and dizzy, which can cause nausea and vomiting.

Treatment for nausea in the morning depends on the cause.

Women experiencing morning sickness during the first trimester of pregnancy can try adapting their diet, increasing fluid intake, and taking an antacid. When nausea and vomiting are severe, your doctor might prescribe a histamine blocker or proton pump inhibitor.

When nausea in the morning is caused by your diet or lifestyle, the following may help

  • limit alcohol consumption
  • eat something small right after you wake up
  • stick to a regular sleep schedule
  • avoid a big meal right before bed
  • avoid fatty foods before bed
  • use relaxation techniques to deal with stress

If your morning nausea is the result of an underlying gastrointestinal issue or ear infection, seeking treatment for the issue will usually help relieve nausea and related symptoms.

If you’re taking medication that’s making you nauseated, you should talk to your doctor about your prescription. A doctor might suggest another type of medication or prescribe an anti-nausea drug to help you cope.

If motion sickness is causing nausea, sitting where you get the smoothest ride and looking out into the distance can help. Anti-nausea pills or patches may also help.

You should see your doctor if morning nausea is disrupting your everyday activities, and you have already ruled out pregnancy.

Most of the time, nausea in the morning is not cause for concern. However, ongoing or severe nausea could be a sign of a serious condition.

Nausea in the morning is often associated with pregnancy, but it has a number of other causes. Sometimes, the cause is related to your lifestyle or diet. In other cases, it’s an underlying gastrointestinal problem, illness, or side effect of medication.

You should see a doctor when ongoing morning nausea is getting in the way of your everyday life.