Dehydration occurs when the body loses more fluids than it takes in, leading to an insufficient amount of water and other fluids to carry out normal functions. This imbalance disrupts essential bodily processes, including electrolyte balance and organ function. Common causes include inadequate fluid intake, excessive sweating, vomiting, diarrhea, or certain medical conditions. Symptoms range from thirst, dry mouth, and infrequent urination to more severe signs like dizziness, confusion, and lethargy, which require immediate medical attention.