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 is often caused by some psychological factor including stress, (anxiety, a new sexual partner or situation), fatigue or unresolved relationship problems. Erectile dysfunction can also be related to a temporary factor, such as the loss of a job, financial concerns or even studying for exams.