A common drinking problem around the world involves a failure to drink enough water. This can lead to chronic dehydration, a major contributor to headaches. Symptoms of dehydration can include dry mouth, dry skin, sense of thirst, sleepiness, headache, decreased urine output, and constipation. Dehydration can lead to lethargy, impaired learning, and an increased risk for stroke and heart disease. Keeping your brain well hydrated can help avoid shrinkage of brain tissue, a condition that has been linked with memory problems and Alzheimer’s. Dehydration increases the production of damaged molecules known as free radicals, which also have been associated with a higher risk of developing symptoms of dementia later on in life and can wreak havoc in many ways. Dehydration is the most common fluid and electrolyte problem among the elderly. Perhaps in part because thirst sensation tends to diminish after age 50. The rate of aging and one’s level of water consumption appear to be directly related—dehydration can contribute to premature aging. More tomorrow.