We have studied the effects of hydrostatic pressure and an uniform electric field on the electron energy levels GaAs-(Ga,Al)As single quantum wells (QWs) and coupled double quantum wells (DQWs) by using the Enderlein's method to solve exactly the Schrodringer equation. Numerical results were obtained using the density of states (DOS) as a function of the applied electric field, hydrostatic pressure, Al concentration, and the geometry as well. We found that the quasistationary ground and excited states energy diminish with and the applied electric field, increase with the confinement potential and the width of central barrier in the DQW. In the latter structure we observed the anti-crossing between the first and second quasistationary energy levels. We found that the applied electric field and the hydrostatic pressure modify the period of Pulsations in QWs.