Alma 15:3

And also Zeezrom lay sick at Sidom, with a burning fever, which was caused by the great tribulations of his mind on account of his wickedness, for he supposed that Alma and Amulek were no more; and he supposed that they had been slain because of his iniquity. And this great sin, and his many other sins, did harrow up his mind until it did become exceedingly sore, having no deliverance; therefore he began to be scorched with a burning heat.

Guilt creates stress, and stress produces a host of physical ailments. The philosophy of the world tells us to reduce our stress by denying our guilt. The "experts" would have us simply sear our consciences with a hot iron. We eventually learn to sin without feeling guilt. But the gospel tells us to reduce our stress by giving our guilt to Christ through repentance. We stop feeling guilty because we stop sinning and let the Savior heal our consciences. Instead of becoming duller, our spirits become sharper, more sensitive, more ready to change and grow.