Causes and risk factors
Various gastrointestinal and other factors can cause nausea. They include stomach infections, food poisoning or in response to certain smells. Overeating can cause nausea. Conditions like motion sickness, first trimester of pregnancy [morning sickness] can lead to nausea. Nausea can occur as a side-effect of certain medications. Strong emotional responses such as fear, psychological illnesses such as bulimia, and severe pain can cause nausea. Nausea is evident in heart attack, cancer, or therapy for cancer, brain injury or tumor, gastroparesis or slow emptying of the stomach (seen in diabetics), diseases of the gallbladder, pancreatitis, peptic ulcer, GERD, migraine headaches, or food allergies. Excessive amounts of alcohol, sugar or caffeine can cause nausea.
Clinical presentation
Nausea is felt as an urge to vomit. There is a sensation of uneasiness in the stomach. Associated symptoms include vomiting, diarrhea, heartburn, headache, stomach pain, dizziness, etc.
Investigations
Medical history by the patient and clinical examination by the doctor helps in diagnosis. Blood tests are recommended which includes complete blood count, blood electrolyte levels, liver function tests, etc. Urine examination is required. Imaging studies such as x-ray or ultrasonography of the abdomen may be useful for further evaluation.
Treatment
Treatment depends upon the underlying cause. Treatment of the underlying cause must begin promptly. Antibiotics may be necessary if an infection is suspected. IV fluids are given if patient shows signs of dehydration. Anti-emetic drugs [to stop vomiting] are given if necessary.
Other Modes of treatment
The other modes of treatment can also be effective in treating nausea. Homoeopathy is a science which deals with individualization and considers a person in a holistic way. This science can be helpful in combating the symptoms. Similarly, the Ayurvedic system of medicine which uses herbal medicines and synthetic derivates are also found to be effective in treating nausea.
Complications
Complications such as severe vomiting, dehydration, advancement of the underlying disease may occur.
When to Contact a Doctor
One must consult a doctor if nausea is persistent or is accompanied by severe vomiting.
Prevention
Prevention depends upon the underlying cause. Motion sickness can be prevented by chewing something during travelling. Morning sickness can be prevented by medications.
Systems involved
GIT, CNS
Organs involved
Stomach , bowel

