Nausea, with or without vomiting, is common in pregnancy. Morning sickness is often brought on by smelling certain odors or eating certain foods.

Morning sickness is most common during the first three months of pregnancy. It typically starts before nine weeks. Symptoms usually improve by the middle or end of the second three months of pregnancy.

When to see a doctor

Contact your health care provider if:

• You produce no urine or only a little urine that's a dark color
• You can't keep liquids down
• You feel dizzy or faint when you stand up
• Your heart races

The cause of morning sickness is not known. Hormone changes might play a role. Rarely, a medical condition not related to pregnancy, such as thyroid or gallbladder disease, can cause serious nausea or vomiting.

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

• Had nausea or vomiting from other causes before becoming pregnant, such as motion sickness or migraines
• Had morning sickness during a prior pregnancy
• Are pregnant with twins or other multiples

Hyperemesis gravidarum might be more likely for those who:

• Are pregnant with a girl
• Have a family history of hyperemesis gravidarum
• Have had hyperemesis gravidarum during an earlier pregnancy

Mild nausea and vomiting of pregnancy usually won't cause harm.

If left untreated, severe nausea and vomiting can cause a lack of bodily fluids, a condition known as dehydration. It also may lead to an imbalance in electrolytes — the salts in blood that control the balance of fluids in the body. Severe nausea and vomiting may result in less urine output. Research is mixed on whether hyperemesis gravidarum causes poor weight gain for the baby during pregnancy.

There's no sure way to prevent morning sickness. However, taking a daily vitamin supplement before and during pregnancy might help.

Morning sickness is typically diagnosed based on symptoms. If your health care provider suspects hyperemesis gravidarum, you may need an exam along with urine and blood tests.

Treatments for morning sickness include vitamin B-6 supplements (pyridoxine), ginger and drugs such as doxylamine (Unisom). Continuing symptoms might require prescription anti-nausea medications.

Vomiting during pregnancy may cause dehydration and an imbalance of electrolytes, such as sodium or potassium. Extra fluids and prescription medicine are recommended for moderate to severe morning sickness.

If you have hyperemesis gravidarum, you may be given fluids through a vein and anti-nausea medicine in a hospital. Rarely, continuing weight loss might lead to the need for a feeding tube.

Check with your care provider before taking any medicine or supplements during pregnancy.

To help relieve morning sickness:

• Choose foods carefully. Select foods that are high in protein, low in fat and easy to digest. Avoid greasy, spicy and fatty foods. Bland foods, such as bananas, rice, applesauce and toast may be easy to digest. Salty foods might be 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. You don't want to get too full, but an empty stomach can also make nausea worse.
• Drink plenty of fluids. Sip water, real ginger ale or ginger tea. Try to drink 6 to 8 cups of fluids without caffeine each day.
• Pay attention to nausea triggers. Avoid foods or smells that seem to make your nausea worse.
• Take care with prenatal vitamins. If you feel queasy after taking prenatal vitamins, take the vitamins with a snack or just before bed. Or try chewable or gummy versions of the vitamins. 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 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 people find them helpful.
• Acupuncture. A trained practitioner inserts hair-thin needles into the skin. Acupuncture isn't a proven way to treat morning sickness, but some people find it helpful.
• Ginger. Ginger helps relieve morning sickness for some people. Ginger comes in capsules, candies, snaps, real ginger ale and tea made with fresh-grated ginger.
• Hypnosis. Although there's little research on the topic, some people have found relief from morning sickness through hypnosis.
• Aromatherapy. Although there is also little research on this topic, certain scents, normally created using essential oils, can help some people deal with morning sickness.

People who live in a state where marijuana is legal might be tempted to try it as a way to ease nausea. However, the American College of Obstetricians and Gynecologists warns that pregnant people shouldn't use marijuana because the effects of the drug on the pregnant person and baby haven't been well studied. Using marijuana 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 your regular prenatal appointment to talk about morning sickness. Be prepared to talk about how often you have nausea, how often you vomit, whether you can keep down fluids and whether you have tried home remedies.

Have a family member or friend go with you to your appointment, if possible, to help you remember what you hear from your provider. Take a notepad with you to jot down important information.

What you can do

To prepare for your appointment, make a list of:

• Your symptoms, even those you don't think are related to your morning sickness
• All medicine, vitamins and other supplements you take, how much and how often
• Questions to ask your provider

Some questions to ask about morning sickness include:

• Is pregnancy causing my symptoms or could it be something else?
• Do I need tests?
• Will I have nausea and vomiting throughout my pregnancy?
• Is there medicine 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 other questions you have.

What to expect from your doctor

Your health care provider might ask you:

• How bad are your symptoms? Can you keep food down?
• Do you notice certain triggers for your nausea or vomiting?
• Do your symptoms occur at certain times of the day or all the time?
• Does anything make you feel better?
• What, if anything, makes you feel worse?