The lowering of the threshold potential is due to the weakening of the body’s inhibition of sodium ions in hypocalcemia, which increases the inward flow of sodium ions. Subthreshold stimuli that are originally below the threshold potential can also generate action potentials, which lowers the actual threshold potential and leads to an increase in its excitability. In layman’s terms, the threshold potential is the horizontal line at which the cell generates action, and the cell generates action potential only when it reaches the threshold potential. When the ion channel is opened, sodium ions inwardly flow into the cell, and a specific potential difference between inside and outside the cell is formed to generate an action potential. Calcium ions and sodium ions in the body compete with each other, called the competitive inhibitory effect, also called the membrane barrier effect. When patients with hypocalcemia, the body’s calcium ion content decreased, calcium ions on the competitive inhibition of sodium ions is weakened, the ion channels open, under the same circumstances there will be more sodium ions flow into the cell, so that the original can not produce action potential subthreshold stimulation, can also stimulate the cell to generate action potentials, so that the threshold potential level of the actual generation of action potentials decreased, action potentials are more likely to be generated, and the cellular excitability increased. Hypocalcemia is recommended to consult a doctor in time, under the guidance of the doctor to determine the treatment plan, to avoid self-medication blindly.