Stop using Cialis and get emergency medical help if you have: erection is painful or lasts longer than 4 hours (prolonged erection can damage the penis); vision changes or sudden vision loss; or. heart attack symptoms - chest pain or pressure, pain spreading to your jaw or shoulder, nausea, sweating.
For example, we now know that several areas in the brainstem and hypothalamus promote wakefulness by sending arousal signals to the cerebral cortex, the brainâs largest region. These signals come in the form of chemicals called neurotransmitters. When neurons in the arousal areas are active, the cortex remains activated and we stay awake. One area of the brain that promotes arousal is the tuberomammillary nucleus (TMN). Here, neurons release histamine as one of their neurotransmitters. Interestingly, many  anti-histamine  medicines block this arousing signal and cause sleepiness.
Too, because hormone levels change during each menstrual cycle, for some people that will have an impact on arousal. When estrogen levels are highest, that can put a damper on our testosterone, the sex hormone everyone has which is a heavy hitter when it comes to how aroused, or sexually excited, we get.