No, the vagus nerve does not cause sweating, though cold, clammy sweat is a common finding in vasovagal syncope. Sweating is mediated by sympathetic postganglionic cholinergic nerves, and it can be prevented by nerve block or atropine. Excessive sweating of the palms and soles (idiopathic hyperhidrosis) is linked to sympathetic nervous system hyperactivity. Vasovagal syncope (pronounced SING-kuh-pee) is a sudden fainting spell, along with low blood pressure and pallor. In this, blood flow to the brain gets restricted, causing one to briefly lose consciousness. The most common causes of vasovagal syncope are severe pain, emotional stress, and extreme fatigue.