Vomiting is an expulsive reflex of the upper gastrointestinal tract with an act of expelling the contents inside.
This is a protective phenomenon in most cases yet sometimes can be a sign of some other severe disease or disorder.
This vomiting is seen in normal life in case any irritant substances are consumed.
But in case of disease, disorder and injuries especially to the head and spinal cord are worth medical consideration.
Vomiting is induced by gastric related factors, blood related and also brain related factors.
Reasons for vomiting
The reasons for vomiting include mainly two disturbance i.e.
Gastric or gut irritation. This vomiting is due to local gut wall irritation but not CTZ stimulated. This occurs due to
1. Foods irritating to mucous: when one consumes irritating foods like mushrooms etc then gut tries to get rid them by vomiting.
2. Vomiting after drinking: Alcohol is a irritant substance and when one consumes excess alcohol or for the first time there is chance of gastric irritation and leads to vomiting.
3. Poisoning vomiting: Poisons which are irritants to gut mucous can be irritating and leads to vomiting. They can also induce vomiting by acting on brain vomiting center.
4. Indigestion: When one consumes heavy food and there is lack of proper digestion, then in-digested food is sometimes vomited. This is seen in cases like jaundice patients on consumption of fat/oil rich foods.
Central nervous system irritation:
There is a sensitive zone in the brain namely chemoreceptor trigger zone (CTZ ) . When there are any inducing drugs or substances in the blood or cerebrospinal fluid or a heady or spinal injury, it leads to CTZ stimulation which leads to vomiting.
1. Disease related vomiting: Like in fever, headaches, migraines etc, there are chances of vomiting due to indigestion (in gut) or due to CTZ stimulation.
2. Journey related vomiting or Motion sickness: This is a vomiting due to disturbance in balance of the ear saccules. This balance is disturbed when one is in motion in a giant wheel or going in a car or vehicle over hilly turns etc. This is due to nervous system stimulation (para-sympathetic).
3. Vertigo related vomiting/ Vomiting due to dizziness: These two or related some uneasiness in the brain and show explainable symptoms with vomiting.
4. Head injury or spinal cord injury etc. When there is a sudden fall leading to head or spinal injury, it leads to vomiting due to CTZ stimulation or vomiting centre.
5. Snake bites/ insect bites: When there is poison injected into blood by snake or insect, they can cause nervous system disturbances leading to vomiting.
6. Poison consumption for suicide. When poisons like pesticide are consumed they induce vomiting by trigger of CTZ.
7. Vomiting due to asphyxia or lack of oxygen. Lack of oxygen for prolonged period induces a type of brain injury and in some cases leads to fits (epilepsy) and vomiting also.
8. Drug induced: Some drugs when taken for treatment of other diseases can also cause vomiting. Example diclofenac sodium during fever.