Symptoms often include frequent urination, increased thirst, and increased appetite. Humanity will become like the Amesha Spentas, living without food, hunger, thirst, weapons or injury. Other suggested causes for erratic and dangerous kangaroo behaviour include extreme thirst and hunger. Common symptoms are dehydration, nausea, vomiting, fatigue, weakness, increased thirst, excess urination. The boy's thirst for knowledge was insatiable. Polydipsia is excessive thirst or excess drinking. Users can easily forget to consume fluids leading to increased thirst and dehydration. A sense of heat, headache, delirium, rapid pulse, and intense thirst accompanied the sweat. Early symptoms of hypovolemia include headache, fatigue, weakness, thirst, and dizziness. Many Aztecs drank dirty, brackish water because of their severe thirst and contracted dysentery. The characters suffer from starvation and thirst. Abhinavagupta is famous for his voracious thirst for knowledge. He also develops a thirst for blood. She soon gives in to her thirst for blood. Some modern productions take further pains to show the sources of Shylock's thirst for vengeance.