There are various stages of physical response during arousal and sex. Researchers have identified four stages of sexual response: arousal, plateau, orgasm and resolution.
Stage 1: excitement or arousal
When a woman becomes aroused, the blood vessels in her genitals dilate. There is increased blood flow in the vaginal walls, resulting in fluid passing through them. This is the main source of lubrication, making the vagina wet.
Her external genitalia or vulva (including the clitoris, vaginal opening, and inner and outer lips or labia) become engorged (swollen because of the increased blood supply). Inside her body, the top of the vagina expands.
Her pulse and breathing quicken, and her blood pressure rises. She may become flushed, especially on her chest and neck, due to her blood vessels dilating.
Stage 2: plateau
Blood flow to the lower third of the vagina reaches its limit, causing the lower area of the vagina to become engorged and firm. This is called the introitus, sometimes known as the orgasmic platform, and it undergoes rhythmic contractions during orgasm.
The woman’s breasts may increase in size by up to 25% and blood flow to the area around the nipple (the areola) increases, making the nipples look less erect.
As she gets closer to orgasm, her clitoris pulls back against the pubic bone and seems to disappear. A woman needs continuous stimulation in this phase to build up sexual excitement enough for orgasm.
Stage 3: orgasm
Orgasm is the intense and pleasurable release of sexual tension that has built up in the earlier stages, characterised by contractions (0.8 seconds apart) of the genital muscles, including the introitus.
Most women don’t experience the recovery period that men do after an orgasm, and she may have another orgasm if she is stimulated again.
Fewer than one in three women can orgasm from penetration alone. Foreplay is vital for orgasm to occur in most women, and can include stroking erogenous zones and stimulating the clitoris.
Stage 4: resolution
Her body slowly returns to its normal state. Swelling reduces and breathing and heart rate slowdown.
Older women, especially if they have been very aroused and haven’t had an orgasm, might feel aching in the back or pelvis.
