Dehydration results from losing more fluids than you take in. Mild to moderate dehydration is remedied by increasing fluid intake. However, in severe cases, medical attention is needed, according to the Mayo Clinic. Nausea, the sensation of having to vomit, often deters a person from drinking fluids, leading to dehydration. Diarrhea, overexertion through exercise and use of certain medications often result in dehydration and nausea.
Diarrhea
Short-term bacterial and viral infections often prompt diarrhea. Diarrhea lasting less than two days is common. However, longer duration of diarrhea indicates a serious condition and causes dehydration. The National Digestive Diseases Information Clearinghouse specifies that dehydration from diarrhea is dangerous in children and older adults due to vulnerable immune systems. In the case of diarrhea due to infection, nausea may present. Additional causes of diarrhea leading to dehydration include bowel disorders, medication interactions and digestive parasites.
Excess Fluid Loss
Body-fluid loss throughout the day normally occurs from sweating, urine excretion and tears. These fluids tend to replenish easily after drinking water or other beverages containing water throughout the day. Athletes have a high susceptibility to losing fluid through increased physical activity leading to excessive sweating. The Mayo Clinic says that vigorous activity without replenishing water and electrolytes such as sodium causes dehydration. Nausea, vomiting and unquenched thirst may also accompany symptoms of dehydration.
Medications
Medications containing diuretics, which are substances that increase the flow of urine to get rid of excess water, may cause dehydration. Common diuretic medications in use include thiazides, used for treating high blood pressure, and medications used for treating pre-menstrual symptoms. The Mayo Clinic notes that over-the-counter antihistamines used to treat cold symptoms also have diuretic effects that can lead to dehydration. In the case of using medications that cause dehydration, consult with your physician to learn alternatives to staying hydrated while on the medication. Nausea may also come from use of these medications as a result of dehydration.
