Short term effects of not drinking enough water include fatigue, the inability to focus and headaches, and long term effects can range from constipation to kidney stones. In severe cases, dehydration can lead to death, according to WebMD.
Usually, one of the first signs of not drinking enough water is a dry mouth or a feeling of thirst. However, by the time a person feels thirsty, dehydration has already begun. Besides feeling thirsty, people who are suffering from dehydration sometimes suffer from headaches, dizziness, heart palpitations and confusion, notes WebMD. In addition, the person will urinate less frequently, and the urine will be a dark yellow. If dehydration is the culprit behind these health issues, drinking water should alleviate the symptoms.
In some cases, dehydration is brought about due to other health conditions. For example, diabetes, diarrhea and skin infections can all make retaining water difficult for the body.
In other cases, too much exercise can also lead to dehydration. However, one problem athletes commonly face is drinking too much water. When a person drinks too much water, they risk diluting the vital sodium balance within the body. This may cause seizures and confusion. Sports drinks are made to hydrate without ruining the sodium balance and are important for those who exercise more than one hour in warm temperatures.