<s>[INST] Hello, two days ago I used a penis pump and I haven't noticed until two days after that the base on my head there is a hard/big vein.Now this i understand if fully hard, as I normally have big veins and one that runs down the middle more or less of my penis, but that is nor thin which it's normally not.I have played around with the hard/big part and now it's gone down but the base of my penis hurts and I would like to know if I have damaged  the main vain or will it repair it's self.Thanks [/INST] Hello, Vacuum constriction devices are safe and can be used by patients with ED caused by many conditions, including: Poor blood flow to the penis, Diabetes, Surgery for prostate or colon cancer, Psychological issues such as anxiety or depression. An erection obtained by the vacuum constriction device is not the same as an erection achieved naturally. The penis tends to be purplish in color and can be cold or numb. Other side effects can include: A black and blue mark or small area of bruising on the shaft of the penis. This is usually painless and generally will resolve in a few days. The decrease in the force of ejaculation. The constriction band traps the ejaculate or semen at the time of orgasm. This is not dangerous and usually does not cause pain. The semen will usually dribble out once the constriction band is removed. Generally, this does not interfere with the pleasure of a climax or orgasm. You must consult a doctor for physical inspection of your penis. Hope I have answered your query. Let me know if I can assist you further. Take care Regards, Dr K. V. Anand, Psychologist </s>