An apparatus and method for providing a nebula or aerosol to a patient. In one aspect, a nebulizer is pressure sensitive so that nebulization is coordinated with a breathing cycle of the patient. The nebulizer includes a movable gas diverter that diverts pressurized gas across a liquid outlet. The diverter is moved in response to the patient's breathing cycle. In one aspect, a biasing member moves the diverter. According to another aspect of the nebulizer, an annular liquid orifice disperses an aerosol in a radial direction in response to a pressurized gas flow from an orifice located concentrically thereto. Multiple liquid orifices may be provided. In a further aspect of the nebulizer, a reservoir includes an upper, wide portion and a lower narrow portion to apply relatively uniform pressure at a liquid orifice.