Morning sickness is nausea and vomiting that occurs during pregnancy. And, despite its name, morning sickness can strike at any time of the day or night.

Many pregnant women have morning sickness, especially during the first trimester. But some women have morning sickness throughout pregnancy. Management options include various home remedies, such as snacking throughout the day and sipping ginger ale or taking over-the-counter medications to help relieve nausea.

Rarely, morning sickness is so severe that it progresses to a condition called hyperemesis gravidarum. This is when someone with nausea and vomiting of pregnancy has severe symptoms that may cause severe dehydration or result in the loss of more than 5% of pre-pregnancy body weight. Hyperemesis gravidarum may require hospitalization and treatment with intravenous (IV) fluids, medications and rarely a feeding tube.

Common signs and symptoms of morning sickness include nausea and vomiting, often triggered by certain odors, spicy foods, heat, excess salivation or — often times — no triggers at all. Morning sickness is most common during the first trimester and usually begins by nine weeks after conception. Symptoms improve for most expectant mothers by the mid to late second trimester.

When to see a doctor

Contact your health care provider if:

• The nausea or vomiting is severe
• You pass only a small amount of urine or it's dark in color
• You can't keep down liquids
• You feel dizzy or faint when you stand up
• Your heart races

The exact cause of morning sickness is unknown. Hormonal changes are thought to play a role in morning sickness. Rarely, severe or persistent nausea or vomiting may be caused by a medical condition unrelated to pregnancy — such as thyroid or liver disease.

Morning sickness can affect anyone who's pregnant, but it might be more likely if:

• You had nausea or vomiting from motion sickness, migraines, certain smells or tastes, or exposure to estrogen (in birth control pills, for example) before pregnancy
• You had morning sickness during a previous pregnancy
• You're pregnant with twins or other multiples

You might be more likely to experience hyperemesis gravidarum if:

• You're pregnant with a girl
• You have a family history of hyperemesis gravidarum
• You experienced hyperemesis gravidarum during a previous pregnancy

Mild nausea and vomiting of pregnancy typically won't cause any complications to you or your baby.

If left untreated, severe nausea and vomiting can cause dehydration, an electrolyte imbalance, decreased urination and hospitalization. Research is mixed on whether hyperemesis gravidarum causes poor weight gain for your baby during your pregnancy.

There's no way to completely prevent morning sickness. However, avoiding triggers such as strong odors, excessive fatigue, spicy foods and foods high in sugar may help.

Morning sickness is typically diagnosed based on your signs and symptoms. If your health care provider suspects hyperemesis gravidarum, you may need a clinical exam and various urine and blood tests.

If your morning sickness symptoms persist, your health care provider may recommend vitamin B-6 supplements (pyridoxine), ginger and over- the-counter options such as doxylamine (Unisom) for management. If you still have symptoms, your health care provider may recommend prescription anti-nausea medications.

Moderate to severe nausea and vomiting of pregnancy may cause dehydration and electrolyte, such as sodium or potassium, imbalance. Extra fluids and prescription medications are recommended for moderate to severe morning sickness.

Your doctor will talk about how often you have nausea, how many times you have vomited, whether you can keep down fluids, and whether you have tried home remedies. There are a number of prescription medications that are safe to take during pregnancy for nausea and vomiting. Your doctor will recommend a safe option, based on the severity of your symptoms.

Check with your doctor before taking any over-the-counter medications or supplements during pregnancy.

If you have hyperemesis gravidarum, you may need to be treated with intravenous (IV) fluids and anti-nausea medications in the hospital.

To help relieve morning sickness:

• Choose foods carefully. Select foods that are high in protein, low in fat and easy to digest, and avoid greasy, spicy and fatty foods. Bland foods, such as bananas, rice, applesauce and toast may be easy to digest. Salty foods are sometimes helpful, as are foods that contain ginger — such as ginger lollipops.
• Snack often. Before getting out of bed in the morning, eat a few soda crackers or a piece of dry toast. Nibble throughout the day, rather than eating three larger meals so that your stomach doesn't get too full. Plus, an empty stomach may make nausea worse.
• Drink plenty of fluids. Sip water or ginger ale. Aim for six to eight cups of noncaffeinated fluids daily.
• Pay attention to nausea triggers. Avoid foods or smells that seem to make your nausea worse.
• Breathe fresh air. Weather permitting, open the windows in your home or workplace. Take a daily walk outdoors.
• Take care with prenatal vitamins. If you feel queasy after taking prenatal vitamins, take the vitamins with a snack or just before bed. If these steps don't help, ask your health care provider about other ways you can get the iron and vitamins you need during pregnancy.
• Rinse your mouth after vomiting. The acid from your stomach can damage the enamel on your teeth. If you can, rinse your mouth with a cup of water mixed with a teaspoon of baking soda. This will help neutralize the acid and protect your teeth.

Various alternative remedies have been suggested for morning sickness, including:

• Acupressure. Acupressure wristbands are available without a prescription in most pharmacies. Studies on acupressure wristbands have had mixed results, but some women seem to find the wristbands helpful.
• Acupuncture. With acupuncture, a trained practitioner inserts hair-thin needles into your skin. Acupuncture isn't a proven way to treat morning sickness, but some women seem to find it helpful.
• Ginger. Herbal ginger supplements seem to alleviate morning sickness for some women. Most research suggests that ginger can be used safely during pregnancy, but there's some concern that ginger may affect fetal sex hormones.
• Hypnosis. Although there's little research on the topic, some women have found relief from morning sickness through hypnosis.
• Aromatherapy. Although there is also little research on the topic, certain scents, normally created using essential oils (aromatherapy), can help some women deal with morning sickness.

Some women might be tempted to try marijuana as a way to ease nausea if they live in a state where it's legal. However, the American College of Obstetricians and Gynecologists warns that pregnant women shouldn't use marijuana because the effects of the drug on mother and baby haven't been well-studied. Additionally, chronic marijuana use may result in a nausea and vomiting syndrome called cannabinoid hyperemesis syndrome.

Check with your health care provider before using any herbal remedies or alternative treatments to relieve morning sickness.

You can usually wait until a routine prenatal appointment to talk to your doctor about morning sickness.

What you can do

To prepare for your appointment:

• Write down any symptoms you're experiencing. Include all of your symptoms, even if you don't think they're related.
• Make a list of any medications, vitamins and other supplements you take. Write down doses and how often you take them.
• Have a family member or close friend accompany you, if possible. You may be given a lot of information at your visit, and it can be difficult to remember everything.
• Take a notebook or notepad with you. Use it to write down important information during your visit.
• Think about what questions you'll ask. Write them down, listing the most important questions first.

Some basic questions to ask about morning sickness include:

• Is pregnancy causing my symptoms or could it be something else?
• Do I need any tests?
• Will I have nausea and vomiting throughout my entire pregnancy?
• Are there any medications I can take to help with my symptoms?
• Does morning sickness pose any risk to my baby?
• What can I eat or drink to help my queasiness?

Don't hesitate to ask follow-up questions as they occur to you during your appointment.

What to expect from your doctor

Some potential questions your health care provider might ask include:

• How long have you had symptoms?
• How often do you experience bouts of nausea or vomiting?
• How severe are your symptoms? Are you able to keep food down?
• Do you notice certain triggers for your nausea or vomiting?
• Do you experience your symptoms at certain times during the day or all the time?
• Are you taking a prenatal vitamin? Do you regularly take any other medications?
• Does anything make you feel better?
• What, if anything, makes you feel worse?