Pulpitis is a severe pain manifestation caused by bacterial infection of the dental pulp tissue. If pulpitis is not treated in a timely manner, and it develops to a late stage, it might intensify the pain. In the early stages, the pain may only occur when eating or due to temperature sensitivity. In the later stages of pulpitis, spontaneous pain may occur, meaning that the teeth may hurt without any external stimuli, or symptoms of nighttime pain might appear, often causing pain at night or pain that can awaken someone from sleep. In its late stages, pulpitis can also develop into pus formation in the pulp tissue, also known as suppurative pulpitis, characterized by pain relief with cold and exacerbation with heat, meaning that cold water can relieve the pain, while hot water can worsen it.