Arousal is the feeling of being turned on sexually. When you’re turned on, your body experiences physical and emotional changes. Your penis or clitoris may get erect (hard), engorged, and sensitive, and you may feel wetness on your vulva or vagina, or on the tip of your penis.
You can become aroused from sexual stimulation alone or with a partner, fantasizing or having sexual thoughts, or reading, watching, or listening to erotic materials (like porn). Arousal can also happen when certain parts of your body are touched that is very sensitive (also called "erogenous zones"). But not everyone feels sexually aroused from touch.
Feeling aroused can lead to many physical reactions or none at all. Some of the changes that can happen to your body when you’re aroused include:
Your blood pressure, heart rate, breathing, and temperature goes up
Your nipples, labia, and clitoris fill with blood and become more sensitive
Your penis gets harder and stands up (this is also called getting an erection)
Your vagina lubricates (gets wet) and expands