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.
Most erectile dysfunction is caused by a physical condition that affects the nerves or blood vessels responsible for erections. Causes include diabetes, vascular disease, multiple sclerosis, Parkinsonâs disease, surgery or radiation therapy for prostate cancer, or the side effects of medication. Psychological causes include anxiety, depression, or stress.