Participants of the Milk challenge typically end up vomiting most of the milk they consume, as proteins in the ingested milk (such as casein) rapidly denature and unravel on contact with gastric acid and protease enzymes, rapidly filling the stomach. Once the stomach becomes full, stretch receptors in the stomach wall trigger signals to vomit to expel any further liquid the participant ingests. People suffering from nausea may induce vomiting in hopes of feeling better. Miscellaneous
After surgery (postoperative nausea and vomiting)
Disagreeable sights or disgust, smells, sounds or thoughts (such as decayed matter, others vomit, thinking of vomiting), etc. Extreme pain, such as an intense headache or myocardial infarction (heart attack)
Extreme emotions
Cyclic vomiting syndrome (a poorly understood condition with attacks of vomiting)
Cannabinoid hyperemesis syndrome (similar to cyclic vomiting syndrome, but has cannabis use as its underlying cause). High doses of ionizing radiation sometimes trigger a vomit reflex. Violent fits of coughing, hiccups, or asthma
Anxiety
Depression
Overexertion (doing too much strenuous exercise can lead to vomiting shortly afterwards). Rumination syndrome, an underdiagnosed and poorly understood disorder that causes patients to regurgitate food shortly after ingestion. Other types
Projectile vomiting is vomiting that ejects the gastric contents with great force. It is a classic symptom of infantile hypertrophic pyloric stenosis, in which it typically follows feeding and can be so forceful that some material exits through the nose. Treatment
An antiemetic is a drug that is effective against vomiting and nausea.
Combined with the resulting alkaline tide, this leads to hypochloremic metabolic alkalosis (low chloride levels together with high HCO−3 and CO2 and increased blood pH) and often hypokalemia (potassium depletion). The hypokalemia is an indirect result of the kidney compensating for the loss of acid. With the loss of intake of food the individual may eventually become cachectic. A less frequent occurrence results from a vomiting of intestinal contents, including bile acids and HCO−3, which can cause metabolic acidosis. Mallory–Weiss tear
Repeated or profuse vomiting may cause erosions to the esophagus or small tears in the esophageal mucosa (Mallory–Weiss tear). This may become apparent if fresh red blood is mixed with vomit after several episodes. Dentistry
Recurrent vomiting, such as observed in bulimia nervosa, may lead to the destruction of the tooth enamel due to the acidity of the vomit. Digestive enzymes can also have a negative effect on oral health, by degrading the tissue of the gums. Pathophysiology
Receptors on the floor of the fourth ventricle of the brain represent a chemoreceptor trigger zone, known as the area postrema, stimulation of which can lead to vomiting.