It is known that ED risk increases with cigarette smoking and this may result from bad effects on penile bloodflow which may occur with changes in heart rate variability (HRV). Low heart rate variability (HRV), associated with nicotine intake (chronic smoking or nicotine gum) may lead to ED, and in some cases increased risk of arrhythmia and sudden death. Men with ED have also been noted to have dysregulated HR (low cardiac autonomic tone), indicating a link between smoking, heart rate variability, and erection. A recent study from Boston University in May 2014 UROLOGY journal reveals that among 22 healthy nicotine naive men, acute nicotine gum ingestion (versus placebo gum) may lead to dysregulation of HRV which was also related to decreased erectile capacity. No changes in sexual arousal, however were noted. While additional larger studies are needed with older men and with penile ultrasound to further identify bloodflow changes, this may be yet another reason for men to try to quit smoking.