Why do we vomit when are sick?

Vomiting is a protective reflex action of the body that helps expel harmful substances from the stomach and intestines. When you're sick, your body may produce toxins or bacteria that irritate the lining of your stomach and intestines. This irritation triggers the vomiting reflex, which causes your stomach muscles to contract and expel the contents of your stomach through your mouth.

Vomiting can be caused by a variety of illnesses, including:

* Gastrointestinal infections: Vomiting is a common symptom of gastrointestinal infections, such as food poisoning, norovirus, and rotavirus. These infections can cause inflammation and irritation of the stomach and intestines, which leads to vomiting.

* Stomach flu: The stomach flu, or viral gastroenteritis, is another common cause of vomiting. This viral infection can cause inflammation of the stomach and intestines, leading to vomiting, diarrhea, and abdominal pain.

* Food allergies: Vomiting can also be caused by food allergies. When you eat a food that you're allergic to, your body's immune system produces antibodies that attack the food. This can cause inflammation and irritation of the stomach and intestines, leading to vomiting.

* Motion sickness: Motion sickness is a condition that can cause vomiting when you travel by car, boat, or plane. Motion sickness is caused by the conflicting signals that your brain receives from your eyes, ears, and inner ear. These conflicting signals can cause nausea and vomiting.

* Pregnancy: Vomiting is a common symptom of early pregnancy. This is thought to be caused by the hormonal changes that occur during pregnancy.

In most cases, vomiting is a temporary condition that will resolve on its own within a few days. However, if you experience vomiting that is severe or persistent, it's important to see a doctor to rule out any underlying medical conditions.