MedicineNet.com

Sexually Transmitted Diseases (STDs) Slideshow Pictures Take the Quiz on STDs A Visual Guide to Erectile Dysfunction

Introduction to the sexual response cycle

The sexual response cycle refers to the sequence of physical and emotional changes that occur as a person becomes sexually aroused and participates in sexually stimulating activities, including intercourse and masturbation. Knowing how your body responds during each phase of the cycle can enhance your relationship and help you pinpoint the cause of any sexual problems.

What Are the Phases of the Sexual Response Cycle?

Sexual Response Cycle

The sexual response cycle has four phases: excitement, plateau, orgasm, and resolution. Both men and women experience these phases, although the timing usually is different. For example, it is unlikely that both partners will reach orgasm at the same time. In addition, the intensity of the response and the time spent in each phase varies from person to person. Understanding these differences may help partners better understand one another's bodies and responses, and enhance the sexual experience.

Phase 1: Excitement

General characteristics of the excitement phase, which can last from a few minutes to several hours, include the following:

• Muscle tension increases.
  
  
• Heart rate quickens and breathing is accelerated.
  
  
• Skin may become flushed (blotches of redness appear on the chest and back).
  
  
• Nipples become hardened or erect.
  
  
• Blood flow to the genitals increases, resulting in swelling of the woman's clitoris and labia minora (inner lips), and erection of the man's penis.
  
  
• Vaginal lubrication begins.
  
  
• The woman's breasts become fuller and the vaginal walls begin to swell.
  
  
• The man's testicles swell, his scrotum tightens, and he begins secreting a lubricating liquid.