Peyronie's disease (PD), a condition that causes the formation of fibrous scar tissue or plaque under the skin of the penis, can cause it to bend, leading to penile shrinkage and a shrinking or shortening phallus when erect. While this curvature is not necessarily cause for concern, it can be extreme and excruciating for PD sufferers. The condition is often a key indicator of vascular and metabolic health, with additional conditions such as high cholesterol, diabetes, and high blood pressure. PD can also affect the wearer's ability to maintain an erection and can lead to physical discomfort. Experts believe the condition is underreported, with patients citing embarrassment or fear of treatment as barriers to reporting symptoms.