Nausea and vomiting, commonly known as morning sickness, is a common symptom experienced by many pregnant women. While it is most common during the first trimester, some women may continue to experience it into their second trimester, including the 4th month. The exact cause of morning sickness is not fully understood, but hormonal changes, increased levels of human chorionic gonadotropin (hCG), and a heightened sense of smell are believed to contribute to this condition. Additionally, factors such as stress, fatigue, certain smells or foods, and an empty stomach can trigger or worsen nausea and vomiting. It's important to stay hydrated by sipping fluids throughout the day and eating small meals frequently instead of large ones. Ginger tea or candies may also help alleviate symptoms. If your vomiting becomes severe or you're unable to keep any food or liquids down for an extended period, it's crucial to consult your healthcare provider as this could be a sign of hyperemesis gravidarum or other complications that require medical attention.