Weight loss often results from prolonged nausea, which decreases the appetite and may be accompanied by vomiting and diarrhea. Nausea and weight loss can be symptoms of a wide variety of conditions, from starvation to infections or cancer. The underlying cause of nausea and weight loss will determine what treatment is necessary. In general, treatment will consist of addressing both the cause and the symptoms.
Nausea and weight loss can result from starvation, which is a condition in which a person does not take in adequate nutrition over a long period of time. Starvation can be either self-induced, as in the case of anorexia, or it can be the result of poverty. In either case, the key to treatment is to reintroduce food slowly so that the person's body does not reject it. Anorexia will also require psychological or psychiatric treatment to help the patient avoid relapsing.
Viral or bacterial infections of the digestive system, known as stomach flu or gastrointeritis, may also lead to nausea and weight loss. Bacterial infections can be treated by antibiotics, which can be administered orally if the patient can hold down medicine without vomiting, or otherwise by injection. Viral infections, on the other hand, do not respond to antibiotics, but will be eliminated by the body within a few days. Patients with either type of infection should be given fluids regularly to avoid serious dehydration and other complications. Eating plain, easily digestible foods, such as saltine crackers, may help reduce nausea and slow weight loss.
Nausea and weight loss are also sometimes symptoms of certain types of cancer, especially cancers of the digestive system. Cancer cells may damage the digestive organs, causing nutrients not to be digested properly even before other symptoms of cancer develop. Weight loss without other identifiable causes may then be due to cancer. Unfortunately, many cancer treatments, such as chemotherapy, also result in nausea and weight loss. These side effects of cancer treatments may be treated using anti-nausea medications or anti-emetics, which stop the patient from vomiting.
Most minor stomach irritations will resolve themselves before resulting in noticeable weight loss. On the other hand, patients suffering from prolonged nausea that results in weight loss should see a doctor to determine the cause of their symptoms and decide on an appropriate course of treatment. Particularly in young children, weight loss can be very dangerous and may result in permanent organ damage.