Nausea is the sensation of wanting to vomit which generally appears as a spontaneous reaction of the body when facing unusual stimuli. Simply put, nausea is a self-defense instinct that every human has in order to avoid danger.
The cause of the sensation of nausea alias arises because there is something that triggers the nervous system in your brain overreacting. The part of the nerve that regulates the onset of nausea is the chemoreceptor trigger zone (CTZ).
This zone will react by producing signals to be sent to the digestive system in the stomach to cause nausea, once the brain detects something suspicious is entering the body. Nausea can then trigger vomiting to expel these foreign substances by mouth because they are considered dangerous.
So, what kinds of things or stimuli can cause nausea? The average cause is a foreign substance that enters the body, whether it is consumed by mouth or inhaled. For example certain drugs, food or drinks that are contaminated with germs, to the pungent odors such as the smell of rotten garbage or stale food.
The cause of nausea can also occur when the body performs unwanted repetitive movements. For example, the body rocking while riding a ship or in a car, or when playing in a game vehicle.
Stomach acid recurs
Digestive disorders or diseases that make stomach acid rise to the esophagus can be a cause of nausea. Examples are dyspepsia (gastritis) or GERD.
These two diseases are marked by the weakening of the sphincter muscle that separates the esophagus from the stomach, so it cannot close tightly. As a result, food that has been digested and mixed with stomach acid can leak back down the throat.
Sour taste and heat that feels in the mouth with belching and coughing can cause people with gastritis or GERD often feel nauseous.
Infections of the digestion
Digestive ailments caused by infections, such as vomiting and food poisoning, commonly cause symptoms of nausea.
Nausea arises when infectious germs (bacteria, fungi, viruses, or parasites) attack the stomach wall and intestinal lining, then produce toxins. This infection then triggers the immune system to order the digestive organs to produce more fluid.
Eventually, the brain will trigger nerves in the stomach to give rise to nausea and the desire to vomit as an effort to remove substances that are considered toxic to the body.
The most common and common cause of nausea is when you travel by vehicle such as by car, plane or train. This happens due to mixed signals sent to the brain by the eyes and inner ear.
When you are in a speeding vehicle, the body generally remains in a sitting and silent position. However, your eyes and ears who look out the window during the trip will see that everything moves backwards and causes unusual reactions.
This “weirdness” makes a part of the brain called the thalamus send a signal throughout the body that something is wrong. Supposing, tell you that, “Hey, why is your body still but the others around you keep moving?”
By the brain, eye and ear movements that are not in accordance with the body are considered as a danger. Thalamus will also cause nausea reactions as a way to stop the “danger”.
Anxious or panicked
Anxiety and panic or nervousness are the body’s natural reactions to stress which can trigger a variety of psychological and physical symptoms, one of which is nausea. So when you are anxious or panicked, for example while waiting for a job interview, do not be surprised if you suddenly feel nauseous.
Stress causes increased production of the hormone serotonin in the body. In addition to making the heartbeat faster and shorter breathing, the hormone serotonin is known to increase acid production in the stomach.
In response to any abnormal bodily functions, the brain will trigger nauseous reactions and possibly even vomiting.