Morning sickness: Causes, concerns, treatments

Why do they call it morning sickness when I feel nauseated all day long? "Morning sickness" is a misnomer. (In fact, the technical medical term is "nausea and vomiting of pregnancy.") For some pregnant women, the symptoms are worse in the morning and ease up over the course of the day, but they can strike at any time and, for most women, last all day long. The intensity of symptoms can vary from woman to woman, too. Video Inside pregnancy: Weeks 1 to 9 A 3D animated look at a baby in the first trimester of pregnancy. Inside pregnancy: Weeks 1 to 9See all videos Overall, this condition affects about three quarters of pregnant women during the first trimester. About half of pregnant women suffer from both nausea and vomiting, one quarter have nausea alone, and one quarter luck out altogether. The nausea usually starts around 6 weeks of pregnancy, but it can begin as early as 4 weeks. It tends to get worse over the next month or so. About half of the women who get nausea during pregnancy feel complete relief by about 14 weeks. For most of the rest, it takes another month or so for the queasiness to ease up, though it may return later and come and go throughout pregnancy. A small percentage of women have symptoms that persist continually (or nearly so) until delivery. Of course, just because morning sickness is common—and likely to last "only" a few months—doesn't mean it's not a challenge. Even a mild case of nausea can wear you down, and bouts of round-the-clock nausea and vomiting can leave you exhausted and miserable. Talk with your caregiver about your symptoms and the possibilities for relief. What causes nausea and vomiting during pregnancy? No one knows for sure what causes nausea during pregnancy, but it's probably some combination of the many physical changes taking place in your body. Some possible causes include: •Human chorionic gonadotropin (hCG). This hormone rises rapidly during early pregnancy. No one knows how hCG contributes to nausea, but it's a prime suspect because the timing is right: Nausea tends to peak around the same time as levels of hCG. What's more, conditions in which women have higher levels of hCG, such as carrying multiples, are associated with higher rates of nausea and vomiting. •Estrogen. This hormone, which also rises rapidly in early pregnancy, is another suspect. (It's possible that other hormones play a role as well.) •An enhanced sense of smell and sensitivity to odors. It's not uncommon for a newly pregnant woman to feel overwhelmed by the smell of a bologna sandwich from four cubicles away, for example. Certain aromas instantly trigger the gag reflex. (Some researchers think this may be a result of higher levels of estrogen, but no one knows for sure.) •A sensitive stomach. Some women's gastrointestinal tracts are simply more sensitive to the changes of early pregnancy. Also, some research suggests that women with a stomach bacterium called Helicobacter pylori are more likely to have nausea and vomiting. Not all studies confirm this link, though. •Stress. Some researchers have proposed that certain women are psychologically predisposed to having nausea and vomiting during pregnancy as an abnormal response to stress. However, there's no conclusive evidence to support this theory. (Of course, if you're constantly nauseated or vomiting a lot, you certainly may begin to feel more stressed!)