Nausea

Nausea is a symptom of unease or discomfort in the upper stomach associated with an urge to vomit. It is not always associated with vomiting or retching. Its’s genesis is complex and has many potential triggers and as a consequence it is often thought of as a symptom which can reflect a number of problems, some of which are gastro-intestinal, others are driven by systemic (a disease affecting many bodily systems) disease or psychological factors.

Normal function of the stomach and upper small bowel involves a delicate balance of interactions between the muscles within the stomach, the enteric (gut) nervous system, the neuroendocrine system, parasympathetic and sympathetic nerves and several centres within the brain and spinal cord. Nausea may result from disruption of this delicate balance. Many of the communications between the brain and gut are manifest through the vagus nerve. As a result of the multiple influences on normal gastric function it is perhaps not surprising that nausea may be precipitated by a wide range of conditions. These include, drugs and chemicals (such as alcohol),  cardiac disease, raised intra-cranial pressure, depression, anxiety and pain, balance and motion disorders (such as travel sickness), endocrine disease such as diabetic ketoacidosis and thyroid disease along with pregnancy and metabolic disease such as uraemia.

Treatment depends upon the underlying cause; avoiding and treating the precipitating factors is key, but in the interim symptomatic treatment with anti-emetics is frequently although not invariably helpful.