Morning sickness is a common condition during pregnancy characterized by nausea and vomiting. It typically begins around the 4th to 6th week of pregnancy and is most noticeable in the first trimester, usually peaking around 8 to 10 weeks. Despite its name, morning sickness can occur at any time of the day or night, not just in the morning

. About 70-75% of pregnant women experience morning sickness to some degree. Symptoms include an upset stomach, loss of appetite, nausea, and vomiting. For most women, these symptoms improve or resolve by the beginning of the second trimester (around 13 to 14 weeks), though some may experience it longer, and a small number have it throughout the entire pregnancy

. The exact cause of morning sickness is unknown but is believed to be related to hormonal changes during pregnancy, particularly the rise in human chorionic gonadotropin (hCG) and estrogen levels. Other factors like changes in blood pressure and metabolism may also contribute

. In rare and severe cases, morning sickness can develop into hyperemesis gravidarum, which involves intense nausea and vomiting leading to dehydration and weight loss. This condition may require medical treatment, including hospitalization and intravenous fluids

. In summary, morning sickness is nausea and vomiting during early pregnancy, common and usually temporary, linked to hormonal changes, and manageable with lifestyle adjustments or medical care if severe