Nausea and weight loss are symptoms of a wide variety of health disorders. Digestive disorders and starvation due to eating disorders, such as anorexia, are common causes. Certain types of cancer and their treatments can also cause these symptoms. These symptoms can occur independently, but they commonly manifest together.
Nausea is a feeling of abdominal discomfort, dizziness, and the urge to vomit. Weight loss is a reduction of total body mass because of fluid, bone, or muscle tissue wasting. A person will experience nausea during starvation because of lack of food and fluid intake. The lack of nutrients will produce high levels of chemicals called ketones, which will trigger the nausea and vomiting center in the brain.
Loss of appetite often develops with nausea and vomiting, and weight loss occurs if the lack of food or fluids is significant and prolonged. Some eating disorders, such as anorexia and bulimia, are forms of starvation, and may cause nausea and weight loss. Anxiety and nausea often appear together in patients with these psychiatric problems.
These symptoms may also be caused by a multitude of digestive diseases. Stomach flu, liver disease, and intestinal disorders are some of the diseases that can cause nausea and vomiting. Again, loss of appetite often follows nausea, which will then cause weight loss. Irritation, blockage, or infection may spur the diseases that manifest with these symptoms.
Cancer is another common cause of nausea and weight loss. Stomach, pancreatic, or any form of intestinal cancer, such as colon cancer, can cause these symptoms. Nausea may be traced to malignant growths and hormonal imbalances. When these occur, proteins and calories are usually not absorbed properly, resulting in weight loss.
Weight loss due to cancer is different from starvation. Starving individuals can increase their metabolic rate to counteract muscle wasting. Cancer patients are unable to adjust their metabolic rate and waste proteins. This can lead to progressive weight loss and wasting of the muscles.
The treatments of cancer, such as radiation and chemotherapy, can also cause nausea and weight loss. Chemotherapy drugs can damage stomach cells, which in turn release a chemical called serotonin. This substance can transmit a signal to the part of the brain responsible for vomiting. Radiation therapy directed at the stomach area normally causes nausea one to two days after the treatment. Due to the loss of appetite and the impaired metabolic process, weight loss may happen, especially in the late stages of the disease.