Painful lumps on the penis can have multiple causes, some benign and others more severe, and I recommend that you see your doctor
or a healthcare professional for evaluation of your symptoms and treatment if necessary. A painful lump is usually either a local swelling of tissue due to inflammation or it may represent a new abnormal growth. Certain sexually transmitted diseases can present as local irritations of the genitalia. Herpes often presents as a constellation of very painful blisters that become open wounds. In contrast genital warts may present as single or multiple nodules with cauliflower like appearance. Your doctor or healthcare professional can examine the lesion to assess whether it may be of STD
etiology. Other causes of local swelling and pain can include insect bites or prior mechanical injury
from shear or compression stress. Penis lumps can also be from different growths. These may include cysts or moles. In rare cases, cancer such as squamous cell can also present on the penis as a new growth. Finally, during erection, dilation of the superficial penis veins can also present as local areas of firmness that dissipate with resolution of the erection. In order to determine the cause of your symptoms, please see your doctor for further evaluation.