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.
The physical causes of ED are not only disease-related. There are many other potential causes, including: 1  Surgery: Surgery performed to treat diseases such as prostate cancer and bladder cancer often requires the removal of nerves and tissues round the affected area, which can lead to ED.