Nausea is one of the common, but mostly non-specific, accompanying symptoms of many diseases. An uncomfortable feeling that usually leads to actual vomiting due to its mere presence. However, the nausea also serves as a protective mechanism for the body, for example, if you run the risk of ingesting inedible or health-endangering substances. Even if such substances have already been consumed and have started to cause damage to the body, the urge to vomit is an important alarm signal that conveys that something is wrong. The following guide provides you with detailed information on illness-related and physiological causes of nausea and possible treatment strategies.
Nausea is the badly suppressable feeling or a kind of reflex that you have to vomit, that is, to convey your stomach contents back to the outside as quickly as possible. This is not always followed by the actual vomiting, because often it just remains with the dull feeling of "having to vomit". However, nausea is often equated with vomiting, whereas the term nausea is used for the feeling of vomiting. As a result, you usually read and hear nausea and vomiting together. And the path of origin for nausea and vomiting in the body is the same.
The starting point for nausea and vomiting is the so-called vomiting center. This is localized in the brain stem (Truncus cerebri) and consists of parts of the following brain elements:
- Area postrema - This circumventricular organ lies in the brain in front of the so-called blood-brain barrier, which represents a natural barrier between the blood circulation of the brain and the central nervous system. The area postrema is therefore a brain device for signal transmission between the blood and the brain. In this context, it is the task of this organ to recognize toxic substances in the blood and to pass on corresponding information as quickly as possible to the nerve units of the vomiting center, the so-called nucleus tractus solitarii.
- Nucleus tractus solitarii - This region of the marrow is filled with so-called gray matter, of which scientists still do not know exactly what it actually does. However, the name Nucleus tractus solitarii, or Nucleus solitarius for short, which translates as “taste nucleus”, already gives an idea of the function of this brain region. In the taste core, taste fibers converge, which are not only responsible for recognizing taste impressions, but also stimulate the flow of saliva and the chewing and swallowing movements through appropriate impulses. Furthermore, impulses from the area postrema and the gastrointestinal tract are interpreted in the nucleus tractus solitarii, which necessitate an urge to vomit. Anyone who has noticed short-term increased salivation in combination with the urge to swallow frequently before vomiting has observed the core of taste at work.
- Formatio reticularis - This neural network extends from the elongated medulla to the midbrain and coordinates a whole range of nerve-based brain mechanisms. In addition to breathing, cardiovascular system, emotions and pain, the formatio reticularis, also known as the reticular formation, is also responsible for the coordination of nausea and vomiting.
This complex process of impulses shows that the nausea is caused by a combination of many different factors. For example, different critical tastes or substances in the bloodstream can be responsible for nausea and vomiting. But nerve impulses, such as those that come about with fear, dizziness or an irritated gastrointestinal tract, cannot be ruled out as triggers.
Diseases as the main cause of nausea
As is well known, nausea and vomiting are most often associated with an underlying pre-existing condition. Nausea is a cardinal symptom, especially in diseases of the gastrointestinal tract. This applies in particular to
- Gastrointestinal infections,
- Food intolerance
- and food poisoning,
which are known to affect first of all the digestive tract. The body tries to protect the diseased organ system from overload or from toxins that enter or develop in the stomach and intestines through pathogens or food toxins. Apart from these typical, gastrointestinal-based disease triggers of nausea, there are still some other organ systems that react with nausea in the event of an illness. To be mentioned here in particular:
- Diseases of the brain,
- Diseases of the central nervous system,
- Diseases of the inner ear,
- Diseases of the eyes,
- Diseases of the metabolic system,
- Diseases of the hormonal system
- and mental illness.
Diseases of the brain and central nervous system
Many parents are familiar with the doctor's advice to watch out for nausea and vomiting if the child has fallen on the head. Behind this information is the reflex vomiting as a sign of increasing intracranial pressure as a result of a brain swelling caused by the fall. The increased intracranial pressure causes an irritation of the vomiting center through space-consuming processes, which are particularly hard on the brain nerves. A faulty signal line in the area of the crushing center is quite possible.
There are many reasons for increased intracranial pressure. For example, it is conceivable that a hemorrhage caused by a fall caused cerebral hemorrhage, which then causes the disturbing pressure conditions. In this regard, internal vascular diseases such as hardening of the arteries (arteriosclerosis) or high blood pressure should be mentioned as possible causes of the bleeding. In the worst case, said diseases in the advanced stage cause life-threatening cerebral hemorrhage. Likewise, the increased intracranial pressure can occur due to an inflammation of the brain, a brain tumor or as a side effect of certain medications.
Danger: If nausea and vomiting occur up to 24 hours after a fall or impact on the head, there should always be a possible complication such as a severe concussion can be thought of. In such a case, please see a doctor immediately or call an emergency doctor!
In addition to increased intracranial pressure, there are of course other neurological diseases that can be considered to be the cause of nausea. In particular, various forms of brain infections and brain inflammation, such as meningitis or encephalitis, are repeatedly announced by nausea and vomiting. Likewise, there may be an urge to vomit in the course of a migraine or an epileptic seizure. In the latter, this is particularly dangerous since patients have no control over their bodily functions during an acute attack and therefore there is a risk of suffocation from their vomit.
Psychological causes of nausea and vomiting are closely related to a disturbed impulse line in the brain. However, it is often the senses that go crazy and consequently call the crushing center on the scene. Starting with phobias, which are only too happy to trigger exaggerated stimulus reactions in the nervous system, to eating disorders, in which pathological compulsive behavior misconditions the vomiting center, to addictive disorders, which provoke disturbances in the brain through extraneous intoxicants and stimulants, there are mental illnesses numerous scenarios that may be responsible for the development of nausea. Most of the time, this is a multifactorial event, which due to the increasing stress leads to an activation of the vegetative nervous system and thus to an irritation of the vomiting center in the brain.
Diseases of the inner ear and eyes
Causes associated with a disturbed signal line in the brain create situations in which nausea occurs at a specific location. Well-known is the so-called motion sickness (kinetosis), in which nausea and vomiting occur during the stay on a ship or with passengers in the car, bus or plane. The symptoms are usually made more difficult here if certain activities such as reading or writing are carried out during the trip.
This form of nausea is caused by contradictory impressions. The sense of balance, or the organ of balance in the inner ear, plays a crucial role here. While the sense of balance registers a significant change in position during the voyage, the eyes have the impression of a position that changes little or not at all, which is further reinforced by looking into a book or looking at the wall of a ship's cabin. This leads to false perceptions in the brain, which is overwhelmed with the sensory stimuli and therefore reacts with symptoms such as nausea, vomiting or dizziness.
Important: Even if the symptoms of motion sickness appear to be harmless and usually disappear quickly when the person feels firm ground under their feet again, they should not be taken lightly. In this situation, the body reacts as if it is in a poisoned state and there is always the risk of a pronounced breakdown of the circulatory system!
At this point, however, be warned of causes of illness in the inner ear that permanently impair the sense of balance. An advanced inflammation of the inner ear (internal otitis) is particularly feared in this regard, since if left untreated it can lead to permanent damage to the structures in the inner ear and thus to the organ of balance. In addition, malformations of the inner ear as a trigger for disturbed balance perceptions and the resulting stimulus to vomit should not be underestimated.
In addition, nausea and vomiting are accompanying symptoms of numerous eye diseases in which normal vision is impaired by visual disturbances. In addition to nausea, accompanying symptoms are usually dizziness and headache. Typical diseases of the eyes, which are accompanied by corresponding complaints, are:
- Ocular infarction (optic omalacia),
- Inflammation of the retina (retinitis),
- Squint (strabismus)
- and optic nerve inflammation (neuritis nervi optici).
Diseases of the metabolic and hormonal systems
Some hormone-based diseases are also associated with nausea. Most often, these are processes on the hormone-producing organs of the adrenal glands or parathyroid glands. It's no secret that hormones play a key role in brain functions. This is especially true for the signal line in the brain stem. Examples of signal-disturbing diseases would be in this regard
- Adrenal insufficiency,
- Addison's disease
- and hyperparathyroidism.
But diabetes mellitus can also lead to nausea and vomiting in blood sugar derailments.
With a view to a disturbed metabolism, on the other hand, it is rather digestive organs that induce the nausea. For example, if the liver or kidneys are damaged by diseases, they can no longer adequately perform their detoxification function. The result is an increased accumulation of toxins in the blood, which are then registered by the area postrema and interpreted as the reason for the induction of nausea.
Typical diseases that can lead to a metabolic disorder and in the next step lead to nausea and vomiting
- Inflammation of the pancreas (pancreatitis),
- Fatty liver (steatosis hepatis),
- Cirrhosis of the liver
- and renal failure.
Other causes of nausea
In addition to illness-related factors, there are a number of other factors and situations that can lead to reflex nausea without any real illness value. These include the reflexive stimulus and gag reflex with which the body tries to prevent objects or pieces of food that are too large from accidentally entering the trachea. The reflex arc is triggered by pressure perception of the rear tongue area and the soft, rear palate. A clear example here is the choking and nausea during dental treatments.
On the other hand, the reflex nausea should serve as a protection strategy to protect the body from (potential) poisoning. A very well-known example of this is the feeling of disgust and the gagging stimulus that is often associated with it, when you see or smell spoiled food or toxic substances. This mechanism serves as a warning to the body not to absorb these substances or to move away from the area of action in the case of toxic gases and vapors. If the poisonous substances have nevertheless entered the body, the body initiates the second stage of this protection strategy, in which case there is actually often vomiting.
This effect is also used when you consciously add toxins to your body, for example in the form of drugs, anesthetics and excessive alcohol. The subsequent vomiting is simply the body's solution to get rid of the toxins as quickly as possible or to keep the amount consumed as low as possible.
Speaking of the influence of substances: some medications, which should actually support the affected patient in recovery, trigger nausea, nausea and vomiting as an undesirable side effect. A well-known example is the supply of iron supplements, oral antibiotic therapy or the use of cytostatics for cancer. And even with antidepressants such as citalopram, nausea and vomiting are often listed as possible side effects. In contact with the doctor treating you, it is essential to weigh up the benefits of the therapy compared to the undesirable side effects.
Even during pregnancy, many women are tormented by recurrent nausea and vomiting. This so-called pregnancy sickness can also be classified as harmless under certain general conditions and is tolerated by most women with a lot of composure. Astonishingly, the causes have not yet been finally clarified medically. However, an interplay of the following factors is suspected:
- changed hormone levels,
- increased smell sensitivity,
- increased pressure in the abdomen,
- decreased muscle tension in the stomach entrance
- and stress from the additional burden.
Danger: However, if the expectant mother hardly eats enough nutrients due to pregnancy sickness and loses weight, it is absolutely advisable to discuss the problem with a doctor. In such a case, both the health of the expectant mother and that of the unborn child are at risk.
Of course, nausea and vomiting are first of all determined by the patient himself. When going to the doctor, a detailed survey of the patient about accompanying symptoms and possible underlying diseases, but also about eating habits and lifestyle is important. The subsequent physical examination is then usually carried out using the exclusion procedure. For example, blood, urine and stool samples can be used to find toxins or infectious agents in the samples. Blood tests in particular also reveal important details about the patient's liver and sugar levels. If food intolerance is suspected, allergy tests are also possible. In the event of a possible pregnancy, a pregnancy test is of course also relevant.
To be able to assess the health of the internal organs and especially the brain, imaging methods such as ultrasound, MRI or CT can also be used. If there is reason to believe that there is an increase in intracranial pressure, in addition to a further blood pressure measurement to rule out vascular diseases associated with high blood pressure, emergency medical measures to lower the intracranial pressure are immediately initiated.
Nausea does not always require therapeutic treatment. If nausea occurs once and without vomiting and clearly emotional exceptional states, an already diagnosed pregnancy or short-term perceptual disturbances can be identified as the cause, one can often refrain from therapy. The situation is different, however, if the vomiting actually begins and there is reason to believe that there is a serious health complaint. Depending on the findings, the following measures are then available in addition to the treatment of the underlying disease in order to alleviate the nausea.
Medicinal therapy for nausea is carried out with so-called antiemetics. On the one hand, they can work in the gastrointestinal tract by relaxing the muscles located here and thus weakening the tense muscle stimuli to the brain. On the other hand, many antiemetics also apply directly to the brain and affect the vomiting center, which alleviates the urge to vomit. Appropriate medications are usually used in tablet form, as suppositories or lozenges.
In its mild form, nausea is easy to manage with simple home remedies. In general, it often helps to simply go out into the fresh air for a short time and take a few deep breaths. In the case of travel sickness, for example, it makes sense to take a short break in the fresh air. In order to reconcile the inner ear and the eyes, it can also help to close the eyes or to fix a fixed distant point in a quiet position.
Morning sickness can be combated with a light snack, if possible before getting up. Cookies, pretzel sticks or a cereal bar are ideal here. Since nausea is often associated with a high stress potential, it is also sensible to establish stress-relieving measures in the daily routine for recurring symptoms. Meditation, yoga exercises and breathing exercises would be conceivable here.
As an acute measure, you can also try whether acupressure therapy provides relief according to the approaches of traditional Chinese medicine. Here, certain points are stimulated by external pressure with the fingers and are said to have a positive effect on the vomiting center in the brain. Striking and successful acupressure points for the treatment of nausea can be found at:
- the inside of the wrists,
- below the kneecaps
- and above the eyebrows.
The pressure by the fingers can be varied, but should always be within a tolerable range.
There are also some herbs from the realm of medicinal plants that can be used to reduce nausea and nausea, for example when used as tea or aromatherapy. These include:
- and anise.
It is not without reason that ginger leads the list, because this bulbous plant has made a special name for itself in the past in the treatment of nausea and vomiting. It is also very popular with pregnant women, as no side effects are to be expected from its use. When using homeopathic preparations, especially Nux vomica, Arsenicum album and Pulsatilla are used very successfully. (ma)
Author and source information
This text corresponds to the specifications of the medical literature, medical guidelines and current studies and has been checked by medical doctors.
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- Ashley B. Grossman: Secondary Adrenal Failure, MSD Manual, (accessed Aug 20, 2019), MSD
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- Norton J. Greenberger: Nausea and Vomiting, MSD Manual, (accessed August 20, 2019), MSD
- Monique Weissenberger-Leduc: Nausea and Vomitio - Nausea and Vomiting, in the Palliative Care Handbook, Springer Verlag, 4th edition, 2008