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.
Physical causes of erectile dysfunction. It is always worth consulting a physician about persistent erection problems as the cause of erectile dysfunction could be any one of a number of serious medical conditions.