horse chestnut. n. 1. Any of several trees of the genus Aesculus, especially the European species A. hippocastanum, having opposite, palmately compound leaves, erect clusters of white flowers tinged with red or yellow, and spiny or smooth capsules containing large shiny brown seeds.
Painful erections are very uncommon unless you have recently experienced penile trauma or irritation. Other causes of erectile pain would include: 1  Peyronie's disease. 2  Penile mass. 3  Priapism. 4  Phimosis. 5  Penile Injury.
Erectile dysfunction (ED) occurs when a man is unable to get or sustain an erection firm enough for sexual intercourse. Intermittent ED is common. Many men experience occasional ED. It is generally caused by stress, exhaustion, or similar causes. Occasional ED should not be a cause of concern.