To prevent a vasovagal reaction, a person should lie down and lift his legs, states Mayo Clinic. Sitting down and pulling the head between the knees is also helpful, as it allows blood to flow to the brain.
Patients with histories of fainting should learn their triggers and avoid them, advises Healthline. They should always avoid getting up quickly from a lying position. Patients should tell their doctors whenever they feel like fainting during medical procedures and should never skip meals. They should also drink plenty of fluids and avoid prolonged standing, especially in hot and crowded places, notes Mayo Clinic.
In most cases, a vasovagal reaction does not require treatments, and doctors may show their patients ways of avoiding their fainting triggers, states Mayo Clinic. In severe cases, doctors may suggest drugs such as midodrine and techniques such as wearing compression stockings, foot exercises and tensing the leg muscles when standing. This reduces the pooling of blood in the legs.
A vasovagal reaction occurs from the disruption of the balance between acetylcholine and adrenaline, reports MedicineNet. Stimulation of the vagus nerve from triggers, such as pain, observing an operation and hearing bad news, causes increased production of acetylcholine, causing the blood vessels to dilate and the heart rate to slow. This reduces blood flow to the brain, causing fainting episodes.