Vomiting (also called emesis) is the forceful expulsion of stomach contents through the mouth, often preceded by nausea, retching, increased salivation, abdominal contractions, and a feeling of unease. It results from stimulation of the vomiting center in the brainstem, triggered by a wide variety of causes including gastrointestinal issues (e.g., gastroenteritis from viruses/bacteria, food poisoning, peptic ulcers, gastritis, intestinal obstruction, appendicitis), central nervous system problems (e.g., migraines, motion sickness, concussions, increased intracranial pressure from tumors or bleeding), infections or systemic illnesses (e.g., urinary tract infections, pneumonia, sepsis), metabolic disturbances (e.g., diabetic ketoacidosis, uremia, hypercalcemia), medications/toxins (e.g., chemotherapy, opioids, alcohol, food toxins), pregnancy (morning sickness), or psychological factors (e.g., anticipatory vomiting). Vomit may appear as undigested food, bile (yellow-green), blood (bright red or coffee-ground-like), or fecal material in severe obstruction cases; accompanying symptoms can include abdominal pain, fever, diarrhea, dehydration signs (dry mouth, dizziness, reduced urine), or lethargy depending on the underlying cause.