When you lie down, your teeth hurt a lot, and this is usually a typical manifestation of pulpitis, which is related to the position. The typical manifestations of pulpitis include spontaneous pain, increased pain at night, and the increased pain at night means that the tooth pain will increase after lying down, which is due to the fact that the head is on a level with the body after lying down, and the blood pressure on the head is relatively greater at this time. Usually relatively less blood when upright in the head after lying down significantly increased, the corresponding pressure will also increase, corresponding to the inflammatory area of the pressure increases, the pain will naturally have aggravated the phenomenon. You need to go to a professional dentistry to find the tooth with pulpitis to open the pulp for drainage, and the pain will be relieved immediately.